Build:37853May 21, 2024

Table of contents


We are happy to introduce Acronis Cyber Protect 15 – an AI-powered integration of Data Protection and Cybersecurity. Acronis Cyber Protect 15 integrates backup, disaster recovery, AI-based malware and ransomware protection, remote desktop, and security tools in a single solution.

One integrated solution:

  • Eliminates complexity
  • Delivers new security capabilities
  • Keeps costs down

What's new in Acronis Cyber Protect 15 Update 6

vSphere 8.0 support

  • Agentless VM backup for VMware vSphere 8.0, including vSAN 8.0 support.

Microsoft SQL Server 2022 support

  • Backup for Microsoft SQL Server 2022 databases and entire instances, including application-aware image backups for virtual and physical machines.

New operating systems support

  • macOS 13 Ventura
  • Linux-based operating systems running kernel versions from 5.17 to 5.19

What's new in Acronis Cyber Protect 15 Update 5

Run an on-demand antimalware scan on any folder/drive

  • Users can run an on-demand scan of any file, folder or drive on their workload (workstation), without the need to ask their IT administrator to do this for them.

Additional low-level protection for Acronis Secure Zone

  • With enabled "Self-protection" feature, Acronis Agent will block attempts to tamper with Acronis Secure Zone partition by any non-Acronis processes on file system level.

Compatibility with Dell EMC Data Domain "retention lock" feature

  • Users can create backups on Dell EMC storage devices managed by Data Domain OS with "retention lock" feature enabled.

What's new in Acronis Cyber Protect 15 Update 4

Always-incremental scheme for Acronis Secure Zone

  • Allows to use the Acronis Secure Zone space more efficiently – no need to have periodic full backups that occupy additional space.

One-click recovery

  • Automates the recovery of workloads by using Acronis Startup Recovery Manager.
  • IT staff no longer need to manually recover workloads that cannot boot.

Secured connection to Active Directory over SSL

  • Communications with Active Directory are performed over SSL by default (LDAPS support).

New operating systems support

  • macOS 12 Monterey
  • Linux-based operating systems:
    • AlmaLinux 8.5
    • Debian 11
    • CentOS 8.5
    • CloudLinux 8.5
    • ClearOS 8.5
    • Oracle Linux 8.5
    • Red Hat Enterprise Linux 8.5

What's new in Acronis Cyber Protect 15 Update 3

Centralized License Management

  • Control licensing of entire environment from a single place by registering on-premises installations in Acronis Cyber Protect Cloud
  • Get full control over license distribution between multiple product installations (including isolated environments)
  • Synchronize new and updated licenses automatically with the product
  • Track license usage and plan license upgrades, by having a clear overview of the current license utilization
  • Keep licenses safe in Acronis Cyber Protect Cloud, without a chance to lose license keys due to a local device failure

Convert backup to VM on Scale Computing HC3

  • Migrate your existing physical or virtual workloads into Scale Computing HC3 as standby VMs
  • Keep the VMs created from backups regularly updated with the latest incremental changes from the original source machines. These VMs will be always ready to start and take over the original workload's responsibilities in case disaster strikes

New operating systems support

  • Windows 11
  • Linux-based OSes running kernel versions 4.18 and 5.8, including
    • AlmaLinux 8.4
    • Red Hat Enterprise Linux 8.4
    • CentOS 8.4
    • Oracle Linux 7.9, 8.4
    • CloudLinux 8.4
    • ClearOS 7.7-8.4
  • SUSE Linux Enterprise Server 15
  • CentOS Stream 8

Deprecated support for Windows Server 2008 for Acronis Management Server installation (Windows Server 2008 R2 is still supported)

What's new in Acronis Cyber Protect 15 Update 2

Activation of subscription licenses in air-gapped environments

  • It is now possible to active subscription licenses even when there is no connection to Acronis Account portal, thus enabling to use all the benefits of subscription licensing even in air-gapped environments.

System disk selection rule

  • New disk selection option in a protection plan to dynamically include all volumes from a system disk: "[BOOT+SYSTEM DISK]" rule. Previously it was possible to include only Boot and System volumes separately, rather than all volumes on a system disk.

Switch from GoDaddy to DigiCert certificates

  • All Acronis binaries are now signed with DigiCert certificates
  • Acronis will no longer install root CA certificates along with its components. DigiCert certificates available natively in Windows OS will be used automatically.

What's new in Acronis Cyber Protect 15 Update 1

Tape management: multistreaming

  • A single backup can be written onto multiple tapes simultaneously

Tape management: multiplexing

  • Multiple machines can perform backup to the same tape drive simultaneously

New operating systems support

  • macOS 11 BigSur
  • Red Hat Enterprise Linux 7.8, 8.2
  • Oracle Linux 7.8, 8.2
  • Cloud Linux 7.8
  • CentOS 7.8, 8.2

VMware ESXi 6.7 host configuration restore

  • Host configuration restore was supported for ESXi hosts version 4.1 and later, and this release adds support for ESXi 6.7.

VMware vSphere 7.0 support

  • Agentless backup and recovery of virtual machines running on VMware vSphere 7.0 is fully supported.
  • VMware vSAN 7.0 is fully supported.
  • Limitations in Acronis Cyber Protect 15 Update 1 release:
    • “ESXi configuration” backup is not supported.
    • (Same as for vSphere 6.7) Virtualization Based Security (VBS) option is always disabled on restored virtual machine.
    • (Same as for vSphere 6.7) Trusted Platform Module (TPM) is absent on restored virtual machine.
    • (Same as for vSphere 6.7) VMware vSphere configurations with PMEM datastores are not supported.

“Auditor” role

  • Auditor role provides access to the entire list of cyber protection activities, without possibility to drop any entries or edit settings.

Improved UI for Acronis Cyber Protect Monitor​

Additional details are now shown:

  • The date and time when the machine was last backed up.​
  • The name of the running protection plan​.
  • The progress of the running backup in addition to the time remaining.​

Quick and Full scans for Anti-malware protection in a single protection plan

  • Configure both full and quick anti-malware scans in the same protection plan on independent schedules.

What's new in Acronis Cyber Protect 15

Autodiscovery and remote installation

Simplify the simultaneous installation of multiple agents in the cloud and on-premise.

  • Network-based discovery
  • Active Directory-based discovery
  • Importing a list of machines from a file
  • Automatic applying of protection plans
  • Batch remote installation of agents by using the discovery wizard

Single protection plan covering all aspects of cyber protection

  • Backup
  • Anti-malware protection
  • URL filtering
  • Vulnerability assessment
  • Patch management
  • Data protection map (data discovery)
  • Windows Defender Antivirus and Microsoft Security Essentials management

Smart protection plan

Perform smart remediation actions based on security alerts from Acronis Cyber Protection Operations Centers (CPOC).

Full-stack anti-malware protection for Windows and macOS

  • Real-time protection against malware
  • Cryptomining process detection
  • Ransomware detection
  • On-demand scanning
  • Self-protection: Protect Acronis components (e.g. registry, service stopping, Acronis file protecting)
  • Network folder protection: Protect the data in shared folders on your machine against ransomware
  • Server-side protection: Protect the data in shared folders within your network against ransomware
  • Files quarantine
  • Exclusions management: Specify processes that will not be considered malware; exclude folders where file changes will not be monitored; select files and folders where scheduled scanning will not be executed

Scan backups for malware in local storage, network shares, and Acronis Cloud Storage

Scan disk backups in the local storage, network shares, and Acronis Cloud Storage, in order to detect malware infections

Safe recovery

Safe recovery allows you to restore an OS image without the malware found in it, to avoid reinfection after recovery.

URL filtering that controls the access to malicious URLs

URL filtering allows you to permit or deny access to specific websites based on information contained in a URL list.

  • HTTP/HTTPS interceptor
  • Black/whitelists for URLs
  • Payload analysis for malicious URLs

Vulnerability assessment

Automated verification of system vulnerabilities to cyber threats

Patch management

  • Automatic approval of patches
  • Deployment on a schedule
  • Manual deployment
  • Flexible reboot and maintenance window options
  • Staged deployment
  • Support for patch management of Microsoft and third-party software on Windows desktop and server operating systems

Windows Defender Antivirus and Microsoft Security Essentials Management

  • Enforce settings across multiple machines
  • Collect all Windows Defender Antivirus and Microsoft Security Essentials detection events and display them in the management console

HTML5-based secure Remote Desktop access

Establish a secure RDP connection to your devices right from web console interface, including cross-sites connections, with no VPN pre-requisites

Full-fledged read-only role support

  • Manage roles on a user level.
  • Added support for read-only mode access.

Disk health monitoring

Proactively track disk health status, before an issue happens.

Continuous Data Protection (CDP) for important files and application data

  • Ensures users won’t lose their work in-progress
  • IT controls what is continuously backed up – Office documents, financial forms, logs, graphic files, etc.

Acronis #CyberFit score for protected devices

The #CyberFit protection score includes the following assessments:

  • Anti-malware software is installed
  • Backup solution is available
  • Firewall is available and enabled
  • VPN is enabled and running
  • Full disk encryption enabled
  • NTLM is restricted for outgoing traffic

Protection for Remote Work Tools

Prioritized patch management and antimalware protection for:

  • Zoom
  • Slack
  • Teams
  • Skype
  • Webex
  • Skype for Business
  • TeamViewer

Application-aware backup for VMs on Hyper-V

The new application-aware backup of Hyper-V VMs by the Agent for Hyper-V improves the backup and recovery of Microsoft SQL Server, Microsoft Exchange Server, Microsoft SharePoint, and Microsoft Active Directory Domain Services running on Microsoft Hyper-V.

Finalizing the virtual machine running from backup on Hyper-V

While a virtual machine is running from a backup, the virtual disks content is taken directly from its backup. Therefore, the machine will become inaccessible or even corrupted if the connection is lost to the backup location or to the backup agent. You have the option to make this machine permanent, that is, recover all of its virtual disks, along with the changes that occurred while the machine was running, to the datastore that stores these changes. This process is named finalization.

This process is now supported for both ESXi and Hyper-V.

Scale Computing HC3 hypervisor support

  • Agent-less backup and recovery for Scale Computing VMs
  • Automated remote deployment of Agent for Scale Computing in the form of a virtual appliance

Data protection map (data discovery)

Monitor the protection status of files with classification, reporting and unstructured data analytics.

Forensic Backup

Image-based backup with valuable, additional data added to backups

Remote device wipe

Helps you prevent data loss from stolen devices.

Updated Cyber Protection Monitor

Displays real-time antivirus protection status.

Installation notes

  • Windows Server 2008 is not supported for Acronis Management Server installation starting with Acronis Cyber Protect 15 Update 3.
  • Please, remember to uninstall Acronis Cyber Protect 15 Beta before installing Acronis Cyber Protect 15. Upgrade from Beta is not supported.
  • If you are planning to use Virtual Host/Universal licenses for protection of VMs by running backup agents inside them (agent-based), make sure to review the following KB article describing the licensing specifics:

Issues fixed in Acronis Cyber Protect 15 Update 6 (Builds: 35681, 35802, 35979, 37255, 37420, 37853)

Issues fixed in build 37853 (May 21, 2024)


  • [ABR-356643] After updating Acronis Cyber Protect 15, Microsoft SQL Server and Microsoft Exchange Server application backups cannot be disabled in existing protection plans.
  • [ABR-385228] Generation of registration tokens fails with the error: "No access policies found for subject."


  • [ABR-365700] Updated error messages for the azure-code-signing module.
  • [ABR-377389] Agent update failed with error: "Failed to unparse current Windows version."
  • [ABR-365933] The unit switcher in the Cyber Protect console shows numbers instead of unit names.

Installation and upgrade

  • [ABR-369843] Agent installation fails with the following error if the cmd.exe is missing on the workload: "Cannot launch child process due to platform API error."
  • [ABR-370590] On VMware virtual machines running Windows 2016, the update of Cyber Protection agent fails with the following error: "Could not remove the current version, DetectAzureCodeSigning error 0x2fc0403."
  • [ADP-30410] Dynamic installation or uninstallation of components results in error 500: "Bad gateway."

Issues fixed in build 37420 (February 28, 2024)


  • [ABR-380201] The status of recovery tasks cannot be obtained if a network issue occurs when running the recovery through the command line interface from a remote machine.

Issues fixed in build 37255 (February 2, 2024)

Installation and upgrade

  • [ABR-370329] The remote installation operation initiated by the root organization administrator fails if executed within a child unit context.

Issues fixed in build 35979 (August 7, 2023)

Installation and upgrade

  • [PLTFRM-56064] Upgrade from Acronis Cyber Backup 12.5 Update 4 to AcronisCyber Protect 15 Update 6 does not work.

Issues fixed in build 35802 (July 4, 2023)

Installation and upgrade

  • [ABR-367727] Upgrade from Acronis Cyber Backup 12.5 to Acronis Cyber Protect 15 fails if the "Acronis Management Server" component uses an external Microsoft SQL 2019 database.


  • [ADP-29526] A backup scanning plan may fail with the error "Failed to receive archive password from CredStore: Cannot get secret value" when password-protected encrypted archives are scanned.
  • [ADP-28359] Updating antivirus and patch management definitions fails in air-gapped environments when using local paths for the definition updates.

Backup and recovery

  • [ABR-357214] Recovery operations that require reboot fail if they need to access a backup archive over the network when recovery is initiated for Windows Server 2016 or later with Hyper-V role, and VLAN is configured on the Hyper-V vSwitch level.
  • [ABR-317541] Selecting the original location for file-level recovery is impossible in Linux if the location is on a disk with a label.

Issues fixed in build 35681 (June 13, 2023)

Installation and upgrade

  • [PLTFRM-45328] Unable to access the Cyber Protection console and/or register agents on the management server due to connection failure after upgrade from previous versions (12.5) in some cases.


  • [ABR-336085] Offline activation of the management server is reset and needs to be re-done, when the management server gets Internet access (for example, gets connected online accidentally).


  • [ARC-474] Disk/volume backup metadata may become corrupted in some cases after exporting one or more recovery points from the original archive. When opening/browsing the exported archive, the "Failed to parse XML" or "The archive is corrupted" errors may appear.
  • [ABR-326706] Existing comments for all backups (recovery points) within the archive are overwritten by the latest comment.
  • [ABR-338382] Management → Protection plans: When drilling down into the devices list by clicking on protection plan status ribbon with count of devices completed with errors, warnings, and success, the resulted list of devices appears empty. Filters "errorByPlan", "warningByPlan", "okByPlan" do not work correctly.
  • [ABR-358386] Protection plan configured to perform backup to cloud storage fails after changing the credentials for the cloud storage outside the Cyber Protection console (for example, in Acronis Account) with misleading error message: "To enable backup to the cloud storage, disable the two-factor authentication for your tenant. For more information, click 'Support'."
  • [ABR-359656] Backup to cloud storage always fails when encountering the RPC connection error "The request has failed. Status: '503'" - this error is not re-tried automatically as it should.
  • [ABR-361722] Backup replication, cleanup, or conversion to VM (Off-host data processing) plans may fail with the error "Error task timeout expired" in rare cases (root cause: internal database ID collisions).
  • [ABR-362051] Acronis Tray Monitor always shows that "Real-time antivirus protection" is enabled even if it is disabled in the applied protection plan.
  • [ABR-362591] Backup replication via Management → Backup replication (Off-host data processing) of backup export operations may fail if the backup archive contains spaces or non-Latin characters. Error: "The source location selected for replication does not exist or is not available."

Tape management

  • [ABR-347430] Upgrade from Acronis Cyber Backup 12.5 may cause corruption of the tape database in rare cases.
  • [ABR-337383] The list of backups within an archive on a tape may appear empty in certain scenarios that involve updating the backup archive cache (update from previous builds, tape rescans).
  • [ABR-358815] Some on-demand operations with tape media/drives available in the UI (for example, Tape Inventory) are shown incorrectly, even if the tape drive model does not support these operations natively.


Issues fixed in Acronis Cyber Protect 15 Update 5 (Builds: 30984, 31791)

Issues fixed in build 31791 (March 7, 2023)

Installation and upgrade

  • [ABR-362283] Upgrade installation fails if self-defense is enabled.


  • [ABR-326706] Older comments for backups are overwritten by the latest comment.

Issues fixed in build 30984 (November 16, 2022)


Installation and upgrade

  • [ABR-342772] Acronis snapAPI module installation fails on Debian 10/11 x64/x32 with kernel versions 5.10.0-13.
  • [ADP-22766] Agent update initiated remotely (e.g. not via local installer package) fails with "An unknown error occurred trying to verify the signature of the file" error in some cases.
  • [PLTFRM-43576] Update: installation of Agent for Windows using local installer package fails with "ResolveAccessTokenOperation: Error 0x62753c: Failed to connect to machine 'https://[address]:9877'. HTTP status code: 402." error, in some cases, when there was a "Standard" license assigned prior to the update.
  • [PLTFRM-41128] Offline activation of the management server fails with "Activation file is invalid" error, if the local DNS server returns empty list of IP addresses for certain hostnames ("" for example).
  • [PLTFRM-40212] Acronis "aakore" service fails to start on Windows XP Embedded SP3 x86 after installation.


  • [ABR-326253] After the password for service account under which Acronis services are running has been changed, "Acronis Scheduler2" service still tries to use old password 5 times which may lead to account lockout in AD.
  • [ABR-337236] Reports: downloaded reports with "Disk health" widget do not contain "Forecast" data, even though this data is present in the UI.
  • [ABR-344659] Media Builder: certain drivers may be skipped from adding into WinPE-based bootable media due to failure to parse the .inf files correctly.
  • [ABR-354011] Cancelling "Backup replication" activity does not work until the currently processed archive finishes replication.
  • [ABR-354476] Web console UI: login using "user@domain" format for username fails with "Bad gateway" error ("domain\user" works).
  • [ABR-354728] Web console UI: The "Use this agent to download and distribute patches and updates" option is not properly displayed in some cases.
  • [ABR-355704] Web console UI: Controls for settings of retention rules for "Backup replication" plans (part of "Off-host data processing") behave incorrectly.
  • [ABR-356970] Web console UI: The Acronis account logout button becomes hidden from the UI if the e-mail address for Acronis account is too long.
  • [ADP-19994] The size of the logs generated by "atp-agent" process may exceed 512MB (limit by design).
  • [PLTFRM-44349] The "alerts-feed-manager-ipn.exe" process consumes too many network ports in some cases.

Backup and recovery

  • [ABR-351591] Backups fail with "Backup failed because snapAPI kernel module is not loaded for kernel" error when Agent for Linux is installed on SLED15 SP2/SP3 systems with enabled Secure Boot.


  • [ABR-306827] Backup of ESXi 6.7 configuration fails with error "Failed to connect to ESXi host by using SSH".
  • [ABR-355867] Agent for Scale Computing: backup may occasionally fail with "Legacy I/O has been detected" on clusters under high load/aggressive backup schedule for multiple VMs in parallel.

Units (tenants) management

  • [ABR-312170] The "http://localhost:9877/api/ams/infrastructure/ams" API method call fails for users who are administrators of more than 2 configured units.
  • [ABR-352008] The UI dropdown list of Units (to switch between Units) may be missing for Unit administrators in some cases.
  • [ADP-22300] The option to select "Discovery" agent is missing when "Add machines" operation is executed for multiple machines by a Unit administrator instead of Organization administrator.

Issues fixed in Acronis Cyber Protect 15 Update 4 (Builds: 29240, 29486)

Issues fixed in build 29486 (April 19, 2022)



  • [ABR-339413] Hyper-V cluster: Protection plan for a VM cannot start with "The protection plan cannot be applied or updated as the existing license" error after changing Virtual Host license manually for this VM via web console UI (Details > Change license).

Issues fixed in build 29240 (March 7, 2022)


The list of security-related fixes added in this update is available at


  • [ABR-336109] Virtual Host licenses assignment to VMware ESXi hosts may consume 2 licenses instead of 1.
  • [ABR-330733] "Activation through file" method does not work in Internet Explorer 11 browser due to broken link to "Download the registration file". There is no such issue when using a different Internet browser.
  • [PLTFRM-36284] ASign feature is not available due to incorrect licensing configuration setup.
  • [PLTFRM-36254] Manual assignment of licenses to resources fails with "can't acquire offering item: failed to get policies: too many SQL variables" error when there are 1000+ licenses added. Automatic assignment works ok.
  • [PLTFRM-36143] Licenses re-assignment ("Allocate licenses" button) via cloud license management portal does not work in some cases.
  • [PLTFRM-34939] Licenses allocated to a registered Acronis Management Server instance via cloud management console, may not be correctly synced back to local management console.
  • [PLTFRM-34002] The trial license disabling is not performed correctly under certain conditions when specific production serial numbers are added subsequently while the trial period is still active.


  • [ABR-335289] "Settings" > "System settings" > "Security": changes made to the underlying settings are not reflected in the web console UI. The changes are lost when refreshing this page after clicking Save.
  • [ABR-333661] Registration of an on-premises Acronis Management Server instance in cloud fails because the ID of the machine is duplicated in Acronis cloud database.
  • [ABR-332153] The list of active registration tokens under "Devices" > "Add" > "Manage active tokens" is empty in web console UI.
  • [ABR-329865] Off-host data processing: Backup replication activities are not shown by "Activity types" widget in the Dashboard and Reports.
  • [ABR-328226] "The credentials for location are not specified" error occurs while accessing backup location on SFTP with custom non-default port.
  • [ABR-300469] Update the CentOS version from 7.6 to 7.9 for Acronis Cyber Protect appliance ("All-in-One appliance")
  • [ABR-230664] Archive encryption passwords longer than 100 symbols are not accepted when the archive is accessed from Linux-based bootable media environment.
  • [ADP-8968] Updating the protection definitions process does not support communications over Internet proxy (only direct connection). Protection definitions include antivirus and antimalware definitions; advanced detection definitions; vulnerability assessment and patch management definitions.

Backup and recovery

  • [ABR-336153] Files/folders recovery may not be available in management console UI due to missing "Recover" and "Download" buttons in rare cases when there are 500+ recovery points available for the same file.
  • [ABR-336456] Agent for Linux: Files/folders recovery into "Original location" does not work for recovery into Linux systems which have labels enabled for the volumes (command example: "e2label /dev/sdb1 LABELED").
  • [ABR-330891] Agent for Mac: the "/Users/[username]/Library/CloudStorage/" path is not added into default files/folders exclusions and therefore backup fails when trying to read these files (which is expected, since the files are in cloud).
  • [ABR-330337] Cancelling a recovery activity is taking too much time (10+ minutes), while it should be nearly instant.
  • [ABR-327623] Backup of the cloned machine will be performed into the same archive file, despite the cloned machine has new "MMScurrentMachineID" and "InstanceID" configured.
  • [ABR-322524] MariaDB/MySQL: Pre-data capture command fails when backing up MariaDB/MySQL using scripts from

Cyber protection

  • [ADP-17994] "Software Management" > "Vulnerabilities" page may be loading forever with no timeout or error in rare cases.
  • [PLTFRM-32861] "alert-feed-manager.exe" and "software-inventory.exe" processes have unexpectedly high data usage statistics.


  • [ABR-329045] Agent for Scale Computing: virtual CD-ROM device is missing for the VM restored from cross-platform backup (P2V scenario).
  • [ABR-328810] Agent for Scale Computing: IDE virtual disk controller is used instead of VirtIO when performing cross-platform recovery to Scale Computing HC3 VM (P2V scenario).
  • [ABR-310063] The conversion of backup into VM on Hyper-V may produce unexpected additional .vhdx/.avhdx disks for the converted VM in some cases.
  • [ABR-301109] Subsequent running a VM from backup operations fails with "Failed to mount datastore" error if the agent (for example appliance) was rebooted in the middle of the previous attempt.

Tape management

  • [ARC-425] Files/folders recovery to network share from backups on tapes may fail with "error 0x29b13ec: Internal error"
  • [ARC-422] Files/folders recovery from tapes ignores "File-level security" option settings.
  • [ABR-336433] Incremental backups replicated from network shares to tape may become full, thus consuming excessive tape storage space.

Units (tenants) management

  • [ABR-320848] Re-registration of an agent under different unit via "register_agent" tool may fail in some cases.
  • [ABR-313183] "Tenants are not related" error may appear when switching between different units under certain conditions when unit admins/users are inherited from Active Directory.
  • [ABR-311022] Login into management console fails when using unit admin account which belongs to a child nested Active Directory group. Example: "Group1" group is set as an Acronis unit admin, "Group2" group is a member of "Group1", "UnitAdmin" user is a member of "Group2".

Issues fixed in Acronis Cyber Protect 15 Update 3 (Builds: 28035, 28122, 28405, 28503)

Issues fixed in build 28503 (December 3, 2021)


  • [PLTFRM-34939] Licenses are not synchronized to cloud properly with "No licenses found" message displayed in "Settings" > "License usage" after re-registration of Acronis Management Server in cloud.

Issues fixed in build 28405 (November 29, 2021)


  • [PLTFRM-34627] Licenses may not be synced properly from cloud portal to a registered Acronis Management Server in environments with big amount of resources/licenses.
  • [PLTFRM-34552] Virtual Host license cannot be used for agents running inside the guest OS of the VM (license allows to protect only hypervisors hosts and VMs in agentless mode).
  • [PLTFRM-33998] Perpetual licenses added before update from Update 2 to Update 3 may be lost after registration of Acronis Management Server in cloud portal.
  • [PLTFRM-33839] Acronis Management Server may not be properly unregistered from cloud when unregistration is initiated via cloud portal.
  • [PLTFRM-32588] Excessive licenses quotas may be consumed in environments with mix of hypervisor agents (Agent for VMware/Hyper-V/etc.) and regular agents (Agent for Windows/Linux) installed inside guest OS of the VMs.

Issues fixed in build 28122 (October 22, 2021)


  • [ABR-328987] Scale Computing HC3 hosts do not acquire licenses properly after update from Update 1 or Update 2.
  • [ABR-328157] Devices do not acquire a license automatically when applying a protection plan to 500 or more devices.
  • [PLTFRM-33484] Revoking a license from 1000+ devices simultaneously from "Settings" > "License usage" may fail with "LicenseAndAccount: failed to enrich request: failed to get resources: too many SQL variables"
  • [PLTFRM-33433] Wrong total number of assigned licenses on "Settings" > "License usage" in large environments (>1000 licensed devices).
  • [PLTFRM-33431] The process of offline unregistration of Acronis Management Server does not allow to download the "Confirmation file" properly (requires page refresh).
  • [PLTFRM-33422] Unregistration of Acronis Management Server licensing via cloud console ( fails to revoke the licenses automatically if there were 5000+ devices managed by Acronis Management Server.


  • [ABR-326646] The XML log from "--log" parameter used with "acrocmd" command does not contain an error message even if "acrocmd" command fails.

Issues fixed in build 28035 (October 6, 2021)

Installation and upgrade

  • [ABR-324149] "Vault Manager" component may fail, thus causing inability to browse vaults in a specific upgrade scenario: 12.5.10330 → 12.5.16428 → 15.0.27009.


  • [ABR-324675] "acrocmd add license" fails to add trial and subscription licenses.
  • [ABR-321449] Acronis Cyber Protect/Backup Standard Server Essentials perpetual key cannot be assigned to Windows Server Essentials 2019 with Hyper-V role.
  • [ABR-320395] License assigned to "FreeESXi" instance cannot be revoked.
  • [ABR-318119] Bootable media is created in trial mode (with "backup" function disabled) if there was the same serial number added 2 or more times in the Media Builder UI, while creating the media.
  • [PLTFRM-29535] Subscription licenses with 5 year validity period are not handled properly.
  • [PLTFRM-28980] Licenses for Microsoft 365 synced from Acronis Account are not handled properly in some cases.


  • [ABR-325534] Recovery points in personal vaults (for example Acronis Secure Zone) cannot be listed via web console when there are 5000+ agents registered on the management server.
  • [ABR-324780] Protection plan cannot be created with "The same replication location cannot be specified twice" error, if both 1st and 2nd locations are "Defined by script" and the scripts has the same name, even though these scripts have different contents.
  • [ABR-322966] Excessive RAM usage by Cyber Protect Monitor on MacOS 10.14 Mojave.
  • [ABR-315808] Backup to Acronis Storage Node managed locations may fail after update from v15 Update 1 with "SocketError: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed" error.
  • [ABR-315479] Saving a backup plan fails with "HTTP request failure for URL "/api/credentials_store/v2/credentials"" error if Acronis Management Server is using external Microsoft SQL Server database installed on non-English locale which causes Microsoft SQL Server responses to contain unexpected symbols (umlauts for German locale for example).
  • [ABR-312917] Backup locations disappear after performing cross-platform instant restore (run VM from backup) of a backup of VM from Red Hat Virtualization on an ESXi or Hyper-V host.
  • [ABR-308008] Off-host Data Processing plans, such as separate Backup replication, Validation, Cleanup or Conversion to VM plans, do not start on schedule in some cases.
  • [PLTFRM-31343] Excessive memory usage by Alerts-Feed-Manager-ipn.exe process.
  • [PLTFRM-29650] In rare cases Acronis services (ASM + APIGW) fail after some time when Acronis Management Server is installed on CentOS, due to low default limits of "Global TCP connections".



  • [ABR-321984] Backup and recovery of VMs on VMware ESXi environments provided by "OVH" provider fails with "Failed to open virtual disk" in some cases. Error from VMware VDDK log: "VMware_VDDK: while parsing HTTP response for method findAllByDnsName".
  • [ABR-320394] List of vSAN datastores is empty when configuring VM recovery, VM replication or Instant Restore (Run VM from backup). Error: "Failed to obtain the virtual machine storage list."
  • [ABR-302481] VM recovery to Scale Computing HC3 cluster fails with "Property 'CpuType' is not supported." error in some cross-platform (X2V) recovery scenarios.

Cyber protection

  • [ADP-17108] Software inventory consumes excessive network bandwidth in some cases.
  • [ADP-16751] Patch management: the agent uses incorrect search criteria when discovering Windows updates, which results in failure to install some updates.
  • [ADP-16721] Detected malware threats cannot be put into quarantine if there are network connection issues with Acronis DC.

Tape management

  • [ABR-322649] Read operations from tape media is slower than expected due to lack of caching for some operations.
  • [ABR-320162] Backup of a multi-disk/volume Linux machine for a single disk/volume to tape location managed by Acronis Storage Node fails with "Input/output" error on 3rd and later attempts.
  • [ABR-319070] Tape total capacity is changed to wrong value in web console UI after first backup.
  • [ABR-316563] Tape pools may be missing in some cases after upgrade from 12.5 or update from older builds scenarios.

Roles and units management

  • [PLTFRM-32494] Users from an Active Directory group, which is a part (child) of "Administrators" Active Directory group, cannot be used to login as unit administrators, unless these users are added directly as unit administrators.

Issues fixed in Acronis Cyber Protect 15 Update 2 (Builds: 26981, 27009)

Issues fixed in build 27009 (May 15, 2021)

Installation and upgrade

  • [ABR-315808] Backup to a managed vault on Acronis Storage Node fails with error “SocketError: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed” after update from Acronis Cyber Protect 15 Update 1.

Issues fixed in build 26981 (May 7, 2021)

Installation and upgrade

  • [ADP-12809] Remote installation of agents fails when automatic redirection from http to https is enabled in C:\ProgramData\Acronis\ApiGateway\api_gateway.json on Acronis Management Server.
  • [ABR-313197] Installation of Agent for Linux fails with "Error 0x28a0001: Can't get ID of the 'acronis' group" error, if /etc/group contains more than 10 users (more than 200 total characters in user names).
  • [ABR-311608] Additional "Acronis" folder (e.g. C:\Program Files\Acronis\Acronis\) is created during upgrade from Acronis Cyber Backup 12.5 Update 5.
  • [ABR-311201] "Backup Storage" section cannot be opened in web console interface after upgrade from Acronis Cyber Backup 12.5 Update 5 in rare cases.
  • [ABR-311095] Installation of Acronis Management Server using external PostgreSQL DB fails with "authentication method 10 not supported" error due to missing support for scram-sha-256 authentication method.
  • [ABR-309615] Backups stored on tape drives may be missing due to improper update of the internal tape DB after upgrade from Acronis Cyber Backup 12.5 Update 5 and in some update from previous Acronis Cyber Protect 15 builds scenarios.
  • [ABR-309578] Upgrade from Acronis Cyber Backup 12.5 Update 5 fails if there is an ampersand symbol in either an archive name or the name of the Acronis Storage Node managed tape location where this archive is stored.
  • [ABR-308646] Acronis Management Server on Linux (including All-in-One Appliance): the "credentials store" DB is not updated properly after update from previous builds or upgrade from Acronis Cyber Backup 12.5. As the result the protection plans cannot be edited and saved, if the backup location require a password (cloud or network share).
  • [ABR-307253] "Devices" → "All Devices" and "Machines with agents" sections may be missing in web console after upgrade from Acronis Cyber Backup 12.5 and in some update cases.
  • [ABR-306567] "VM replication" tasks Activities list is empty after upgrade from Acronis Cyber Backup 12.5 in some cases.
  • [ABR-305635] The protection plans may be missing after upgrade from Acronis Cyber Backup 12.5 in some cases. Error during upgrade: "POR: Cannot access property by path '.Hash'."
  • [ABR-305541] Remote installation of Agent for Windows fails if the previous remote installation attempt was unsuccessful due to presence of "C:\Windows\Temp\AcronisRemoteInstall" leftover folder.
  • [ABR-304951] Rescan of tape backups stored on tape locations managed by Acronis Storage Node may crash after upgrade from Acronis Cyber Backup 12.5 in rare cases.
  • [ABR-297965] "aakore" service uses port 9999 instead of dynamically assigned port during installation of Acronis Management Server or Agent components, which may cause installation to partially fail (registration of the component failure) if the 9999 port is busy.


  • [PLTFRM-27539] Backup console cannot be opened after disabling "Sign in as the current Windows user" option (in account_server.json file).
  • [ADP-12982] Reports and monitoring: "Device status" column in "Activities" widget shows invalid info.
  • [ADP-12737] Alerts Feed Manager service logs under \ProgramData\Acronis\AtpAlertsFeedManager\Logs are not rotated properly and may grow too large.
  • [ADP-12657] Update of Cyber Protection definitions by atp_database_mirror.exe may consume excessive network bandwidth.
  • [ADP-12332] Cyber Protection definitions database under \ProgramData\Acronis\AtpDatabaseMirror folder may grow too large.
  • [ABR-312496] It is possible to create a protection plan where backup destination is set to Managed Vault with enabled deduplication and change the archive format to v12 in backup options, which leads to inability to edit such plan, since Managed Vault with enabled deduplication supports only v11 archive format.
  • [ABR-311488] E-mail notifications are sent in English, ignoring the language selection under Settings → System Settings → E-mail notifications → "Notification language".
  • [ABR-310016] "Entire machine" recovery fails to start if "Safe recovery" option is enabled in some cases.
  • [ABR-309152] Acronis Universal Restore option is not available in Media Builder when using Acronis Cyber Protect 15 Perpetual Standard Workstation license.
  • [ABR-308570] "Maintenance has expired" message is wrongly shown even for non-expired licenses in Settings → Licenses for some licenses editions.
  • [ABR-308008] Plans created from "Plans" → "Backup replication" may not start on schedule in some cases.
  • [ABR-306015] Backup option is not available in bootable media UI when the media was created using "Acronis Cyber Backup Standard Workstation" license. Issue affects both subscription and perpetual types of licenses.
  • [ABR-244273] mms.exe and zmqgw.exe may randomly crash during backup and backup replication operations due to an issue in libzmq library.



  • [ABR-307962] Confusing "Deleting hypervisor snapshot" error is always shown even if snapshot removal process completes successfully and is not related to the actual root cause of the failure.
  • [ABR-286485] "FreeESXi" item is not available as a licensed resource when assigning a Virtual Host license.
    The fix for this issue does not revert back the licensing assignment behavior as it was in Acronis Cyber Backup 12.5, and the instructions from are still valid. Refer to the description of issue [ABR-307522] in the "Known Issues" section for details.

Tape management

  • [ABR-307155] Rescanning a tape set which consists of backup archive spread among 2 or more tapes may get suck in endless loop with "Tape media '[ID]' is required to complete the operation." prompts.
  • [ABR-302812] Backup and other operations with centralized tape locations managed by Acronis Storage Node is not possible if the tape location (vault) name contains special symbols, such as ` \ " < > / # { } `

Issues fixed in Acronis Cyber Protect 15 Update 1 (Build: 26172)

Issues fixed in build 26172 (December 29, 2020)

Installation and upgrade

  • [ABR-296987] Agent for Linux: installation on SLES 15 SP2 finishes without snapapi module compilation.
  • [ABR-292093] Newly created protection plans cannot be applied to devices in some cases after chain upgrade from 11.7 to 12.5 to 15.
  • [ABR-277723] Agent for Oracle is missing in Linux installer b. 16470
  • [ABR-255190] Installation of Agent for Windows fails on a machine in domain, if the selected service user name exactly matches the machine name.
  • [ABR-238602] There are duplicate Windows Firewall entries for automatically Acronis-generated inbound rules after upgrade from 12.5.


  • [PLTFRM-24633] The "Assigned to" value is empty for specific licenses, when checking license assignment from Settings > Licenses.
  • [ABR-297498] Free cloud storage is not available for some accounts after sync.
  • [ABR-295298] The available free space value for cloud storage is always shown as 0 bytes after upgrade from v12.5.
  • [ABR-294690] References to previously deleted backup locations on network shares may be still present in the backup console after upgrade from 12.5 in rare cases.
  • [ABR-292137] Backup console: There is no warning when pressing "Stop" button for running protection plan in "Plans" section.
  • [ABR-288928] WinPE-based bootable media: The same network settings configured for 1 NIC in Acronis Bootable Media Builder interface are also applied to 2nd NIC, thus causing conflict when booting from the created media.
  • [ABR-288023] Agent for Linux: Kernel panic occurs when backing up a VXFS volume with block size > 4096b.
  • [ABR-284386] File-level recovery from volume which contains "\System Volume Information\Dedup\" path fails even if NTFS deduplication has been disabled for this volume.
  • [ABR-283927] Web restore accessed from "Devices > Recover > More ways to recover > Download files" fails with "You are logged in as a Read-Only Administrator" error.
  • [ABR-276961] WinPE-based bootable media: "Tools" > "Run the iSCSI setup" action does not work in bootable media interface.
  • [ABR-274169] File-level backup succeeded without warnings if one or more protected managed entities (files or folders) were not found.
  • [ABR-239469] Acronis Management Server: An "In progress" activity cannot be cancelled after the agent which performs this activity was unregistered from Acronis Management Server.
  • [ABR-165944] HP Smart Array P408i-a SR Gen10 driver is incorrectly installed when applying Acronis Universal Restore.
  • [ABR-136232] Agent for Windows: It is not possible to connect via RDP to AWS EC2 VM after cross-platform recovery of disk/volume backup into it, when backup was taken from machine running on non-AWS source platform.


  • [SEC-2721] Cross-site scripting (XSS) was possible in Cyber Protect Console. The issue was assigned CVE-2020-35664, CVSS score 7.3 (high severity)
  • [SEC-2705] Information disclosure was possible due to CORS misconfiguration in local notification service. The issue was assigned CVE-2020-35556, CVSS score 3.6 (low severity).


  • [ABR-292086] Agent for Windows installed inside VMware ESXi VM is treated as physical machine device in case "smbios.reflecthost" parameter is set to "true" in VM properties.
  • [ABR-277151] Recovery of an EFI system with more than 4 partitions on disk to a new Hyper-V VM may fail with "Cannot recover the volume from the disk backup. There is insufficient free space on the target disk." error.
  • [ABR-272872] Hyper-V production checkpoints cannot be created if virtual machine has iSCSI disk connected inside the guest OS.
  • [ABR-232724] Recovery into a VM fails with "Failed to copy source disks to a new virtual machine." and "This action is not supported." for systems where the file system was created directly over the whole disk without creating partitions layout first (Linux-specific).
  • [ABR-155252] Linux-based bootable media: network mapping cannot be changed during ESXi host configuration recovery.

Applications support

  • [ABR-261814] Backup plan applied to Microsoft SQL Server database gets revoked automatically if Microsoft SQL Server instance is stopped for more than 15 minutes, thus leaving the SQL database unprotected.

Tape management

  • [ABR-295217] Tape media are duplicated in Tape Management view in backup console after listing backups on these tapes via "Show backups".
  • [ABR-269207] Backup validation fails with "Tape media 'Tape 001' is required to complete the operation" error instead of prompting for the required cassette.
  • [ABR-266903] Rescanning a tape set which consists of backup archive spread among 2 or more tapes may fail with "The media is offline" error.
  • [ABR-248604] Backup to tape vault managed by Acronis Storage Node may fail with "Data are absent in cache." error.
  • [ABR-207327] Rescanned tapes show incorrect capacity under Tape Management section in backup console.

Roles and units management

  • [PLTFRM-24998] "Administrators" group under Settings > Administrators is unexpectedly re-created after restart of Acronis Service Manager when this group was deleted before.

Issues fixed in Acronis Cyber Protect 15 (Builds: 24426 – 25729)

This section describes issues that have been fixed in Update 6.

Issues fixed in build 25729 (October 31, 2020)


  • [ABR-293820] The error "Failed to establish connection with the agent" is displayed when you try to run a WinPE media file.
  • [ABR-292718] The restore_disaster.bat file cannot be run.


  • [ADP-10779], [ADP-10778], and [ABR-292093] Issues related to the upgrade from Acronis Backup 11.7.

Issues fixed in build 24600 (October 6, 2020)


  • [ABR-289055] You cannot browse files and folders inside disks/volumes backups (not "Entire machine" backups) which were created with enabled inclusion/exclusion rules in the "File filters" backup option.


  • [SEC-2181] The fix for the "Local privilege escalation was possible due to a DLL injection vulnerability" issue is missing in some additional Acronis components.

Issues fixed in build 24538 (September 29, 2020)

Installation and upgrade

  • [PLTFRM-23921] Clicking "Show activity" on old alert inherited from Acronis Cyber Backup 12.5 shows infinite "Loading..." for activity details, after upgrade to Acronis Cyber Protect 15.
  • [PLTFRM-23829] Some names of old "activites" inherited from Acronis Cyber Backup 12.5 are garbled in Dashboard -> Activities after upgrade to Acronis Cyber Protect 15.
  • [ADP-10493] Upgrade of Acronis Cyber Backup 12.5 agent initiated via backup console may fail with "IncorrectTargetHostName" error in some cases.
  • [ABR-290405] Some activities appear with false "pending" status in backup console after upgrade from Acronis Cyber Backup 12.5.
  • [ABR-290239] When using "Create msi and mst files" option in the Acronis Cyber Protect 15 installer, the connection to management server settings are not saved properly in the UI.
  • [ABR-290016] Running a separate "Cleanup" plan may fail with "Internal error. Please try again later or contact support" after upgrade from Acronis Cyber Backup 12.5.
  • [ABR-289796] Existing backup plans for Exchange DAG cluster may fail with "InvalidRequest" after upgrade from Acronis Cyber Backup 12.5.
  • [ABR-289757] Acronis Management Server service fails to start after installation on Windows Server Core.


  • [ABR-290940] Login into backup console may hang due to Acronis Monitoring Service slow response in some cases.
  • [ABR-290893] "Use a disk cache to accelerate the recovery" (from tapes) recovery option is missing in backup console.
  • [ABR-290704] "Weekly", "Daily" and "Hourly" schedule options are missing when configuring backup replication plan from "Plans" section in backup console.
  • [ABR-290668] False "Trial has expired" pop-up message appears in backup console in some cases.
  • [ABR-290245 + ABR-289774] Incorrect information about assigned licenses is shown in "Licenses" section in backup console in some scenarios which involve "Virtual Host" or "Universal" licenses type.
  • [ABR-283927] Web Restore console is unavailable with "You are logged in as Read-Only Administrator" message when using "More ways to recover" option during file-level recovery.


  • [ABR-218999] Backup of XenServer 7.6 Windows VM restored as VMware ESXi VM does not boot with 0x7B BSOD if there were PVM drivers installed in the source system.


  • [SEC-2181] Local privilege escalation was possible due to a DLL injection vulnerability. The issue was assigned CVE-2020-10138, CVSS score 8.1 (high). We want to thank HackerOne researchers @adr, @mmg, @vanitas, @xnand for reporting this to us.
  • [ABR-284823] Improved cipher suites selection for Cockpit web server used in All-in-One Appliance to mitigate vulnerabilities similar to "ROBOT".

Issues fixed in build 24515 (September 21, 2020)

Installation and upgrade

  • [PLTFRM-23745] Acronis Cyber Backup 12.5 Virtual Host license does not remain assigned to the virtual host after upgrade to Acronis Cyber Protect 15.
  • [ADP-10356] Acronis Monitoring Service does not automatically start after system reboot, when management server is installed on Linux. As the result, the Dashboard becomes empty in backup console UI.
  • [ADP-10297] Agent for Linux: Backup plans statuses become OK after upgrade from 12.5 without preserving the original statuses.
  • [ABR-290029] "Devices" -> "Scale Computing" section is missing after upgrade from 12.5 and registration of Agent for Scale Computing.
  • [ABR-288295] Credentials for proxy server connection defined in HttpProxy registry branch, become empty after agent upgrade from 12.5. As the result the agent cannot connect to the management server after upgrade.
  • [ABR-277495] Installation of the backup agent onto Windows Server 2003 via 'msiexec' causes 'msiexec' to crash.


  • [PLTFRM-23597] The "License is required" pop-up notification does not disappear automatically after adding a perpetual license.
  • [SDT-1075] An existing Acronis Cyber Backup Standard subscription period cannot be extended (increase or renew quota) by adding a new subscription license of the same type.
  • [ABR-287622] The devices list may be empty for Acronis Cyber Protect Advanced/Standard Server subscription license in License -> Settings -> "Apply" dialogue in some cases.
  • [ABR-287504] The devices may appear twice (duplicated) in License -> Settings -> Apply dialogue in some cases.
  • [ABR-286616] Dashboard -> Overview is not displayed correctly under high load (multiple users connected to backup console) with "Status code: 500 Internal Server Error."
  • [ABR-286168] It is not possible for Organization admin to edit a protection plan created by child unit admin.
  • [ABR-286154] It is not possible to create a backup location on connected Acronis Cyber Infrastructure storage.
  • [ABR-285544] Changes made in "Performance and backup window" -> "Output speed" settings are not applied after editing a protection plan.
  • [ABR-285757] Default protection plans list is shown in backup console, while there should be no such list.

Cyber protection

  • [ADP-10351] "Software Management" -> "Patches" list is empty in child units created under parent Organization.
  • [ADP-10344] Threat feed: "Run recommended actions" -> "Backup of unprotected machines" action does not work.
  • [ADP-10326] "Microsoft Security Essentials" option in protection plan does not work for 32-bit agents.
  • [ADP-10301] It is possible to create 2 protection plans with enabled URL filtering, while it should not.
  • [ABR-286602] Protection plan with enabled "Vulnerability assessment" option always fails if there is Acronis Cyber Backup 15 Standard perpetual license used.

Application support

  • [ABR-287672] Oracle user does not have access to "/var/lib/Acronis/Oracle" path by default which causes application processing script to fail with "Access denied" error.

Issues fixed in build 24426 (September 09, 2020)

This section describes issues that have been fixed in Acronis Cyber Protect 15 in comparison with Acronis Cyber Backup 12.5 Update 5.

Installation and upgrade

  • [ABR-245958] Agent for Linux installation on CentOS 5.9 fails with "Cannot find package dkms" error.


  • [ARC-207] Backup of large amount of data to Acronis cloud may cause excessive RAM consumption by mms process and fail with "Not enough memory" error in some cases.
  • [ABR-278284] Login and logout events are not recorded in Activities list.
  • [ABR-275420] Agent for Linux: "Backup did not start" alert is falsely triggered in some cases.
  • [ABR-274657] The "Unit" column in the Plans > Protection section grid shows "Root" value instead of "Organization" for all plans.
  • [ABR-264194] Backup archives created via Bootable Media always get "localhost" in their names instead of actual host name of the machine.
  • [ABR-260575] Agent for Mac: file-level backup of specific paths (for example /private/var) always completes with warnings. Access to these files is not possible by design even with "Full disk access" permissions.
  • [ABR-260477] After changing the backup format from v11 to v12 in the protection plan settings, backup replication to a cloud storage fails with the error "The archive is invalid or its type is unsupported."
  • [ABR-253870] "Backup file name" option does not allow to map newly created backup plan to existing encrypted archives (no option to provide password).
  • [ABR-248575] Backup replication plan automatically starts after its schedule has been disabled.
  • [ABR-248395] When selecting network folders as source to backup in "What to backup" section of the backup plan, the "invalid item_key: Internal server error." error may appear in some cases.
  • [ABR-249704] When changing Daylight Saving Time (DST), scheduled backups may fail with the error "Backup with creation date in future was detected".
  • [ABR-249206] "The specified service does not exist as an installed service" error appears when starting AMSAcepReporter.exe task via schedmgr tool.
  • [ABR-239739] Agent for Linux: In some cases, the "Entire machine" backup may not include all Linux volumes/partitions
  • [ABR-239576] Recovery of files or folders does not skip existing files when the "Overwrite existing file if it is older" option is enabled.
  • [ABR-238953] Backup to SFTP immediately fails upon network disconnection without re-try attempts.
  • [ABR-238339] EFI boot entries are restored in non-original order if the restored backup contains non-standard EFI boot entries – for example, "Dell OEM partition".
  • [ABR-237918] Backup agent cannot be re-added to AMS after it was unregistered if it's running on the same machine.
  • [ABR-235902] Recovery of files or folders via acrocmd from a backup in the v11 format fails when using "--file=c:\[folder]\" or "--file=c:\[folder]" syntax, when the [folder] path doesn't exist.
  • [ABR-234633] There is no error message shown in backup console when trying to login while AMS service is stopped.
  • [ABR-230924] Browsing a network share fails when performed by Agent for Linux or bootable media, if the password contains a comma symbol.
  • [ABR-220325] Agent for Mac: Backup does not run on schedule if the scheduling option "Do not start when connected to the following Wi-Fi networks" is enabled, regardless of whether this condition is met or not.
  • [ABR-219758] Backup performance may become slower than expected if the archive is created in v12 (default) format and the archive size is more than ~5 TB.
  • [ABR-219330] Agent for Linux: A backup of an XFS volume with minor AGFL corruption performed in the sector-by-sector mode if the volume resides on a drive with the 4K sector size.
  • [ABR-218410] Files/folders backup from a network share selected as source tries to access this network share without credentials if the "File-level backup snapshot" option is enabled. In some cases, this may result in failures and show the error "Access is denied".
  • [ABR-216182] Recovery of disks/volumes fails when the target location for recovery is a removable drive – for example, an external USB drive.
  • [ABR-202625] When browsing an encrypted archive via Windows Explorer, the password for the archive is prompted only once. No prompt for password when an archive is closed and re-opened via Windows Explorer.
  • [ABR-202548] Agent for Linux: A differential backup of a Linux machine disks/volumes may be of the same size as a full backup in specific cases.
  • [ABR-199432] Backup plans do not run on schedule after changing the user under which the "Acronis Managed Machine Service" (MMS) service is running.
  • [ABR-168401] Adding the same network share as backup location under 2 or more different "units" causes this backup location to disappear from the "units" it was added before.
  • [ABR-139316] Validation of a backup that was created in the v11 format and includes Microsoft Windows Storage Space partition fails with the error "No current partition".
  • [ABR-135320] Incorrect "This machine cannot be selected directly." warning appears in bootable media interface when clicking on host in backup source selection.

Application support

  • [ABR-253768] Editing of an old Exchange DB backup plan may fail with the error "The backup file name does not contain required variables: 'database name'".
  • [ABR-234882] Backup of a single SQL database takes too long if the SQL instance contains many databases (100+).
  • [ABR-234570] Backup of SQL database fails if there is a space in the database path.
  • [ABR-223486] Oracle Explorer tool fails to connect to backup location with "Connection refused" error in some cases.
  • [ABR-219577] Agent for Exchange: If the "Maximum Shadow Copy Storage space" limit is configured in the VSS settings, then this limit becomes "UNBOUNDED (100%)" after the backup of an Exchange database.


  • [ABR-277063] CSV volumes are put into "Redirected access" mode after installing Acronis Agent for Windows on the CSV owner Hyper-V host included in Microsoft Failover Cluster (Windows Server 2012 R2/2016/2019).
  • [ABR-260431] Backup of Hyper-V virtual machine may fail with the error "Cannot access a released resource." if the backup option "Multi-volume snapshot" is disabled. Disabling this option is not supported for backups of Hyper-V virtual machines.
  • [ABR-260173] No warning or alert is generated if a Hyper-V virtual machine backup automatically fails over to a crash-consistent checkpoint due to VSS failure inside the guest OS of the virtual machine – for example when an application-consistent VSS snapshot is not possible.
  • [ABR-258334] Recovery of a Hyper-V virtual machine to SMB3 share on Hyper-V Cluster fails if the path is resolved in the 'smb://server/share' format instead of '\\server\share'.
  • [ABR-248218] VirtIO drivers are disabled after recovery (restore with reboot) of a KVM-based Windows virtual machine to another virtual machine. Recovery via bootable media is not affected by this issue.
  • [ABR-233514] Agent for VMware/Hyper-V: Running a virtual machine from a backup may fail with "Error code: 7 'Disk is not found." in some cases.
  • [ABR-228965] Agent for VMware: VMware ESXi VMs are not displayed in the Devices list, if these VMs have a specific text used in "Annotations" (starts with '<' symbol).
  • [ABR-212285] If a backup was captured by Agent for Windows from a Windows machine which contains LDM volumes, then recovery (X2V) from this backup performed by Agent for VMware/Hyper-V (agent-less) may fail with the "Failed to copy the volume." error.
  • [ABR-206940] Backing up a Hyper-V virtual machine located on a CSV volume may block moving this CSV volume to a different Hyper-V node, in some cases
  • [ABR-204800] Direct SAN Access (LAN-free) mode does not work when Agent for VMware (Windows) is running on Windows Server 2019 and the agent is managing vSphere 6.7 U1 environment
  • [ABR-197411] Agent for VMware: Virtual disk changes from the "Thin provisioning" to "Thick provisioning" mode after VM replication when the source VM disks are located on the NFS-backed datastore.
  • [ABR-194557] Agent for Hyper-V: A Hyper-V VM backup produces the following warning - "Changed Block Tracking (CBT) is not used because there are disk files that do not belong to any disk snapshot." - if there is a tree of Hyper-V VM checkpoints which includes two or more sibling checkpoints with no common parent.
  • [ABR-190721] Agent for VMware: The "The virtual machine may be backed up without using Changed Block Tracking (CBT) because the machine has snapshots." warning is shown after a backup in more cases than it should.

Tape management

  • [ABR-277417] Backup to tape with enabled "Overwrite a tape in the stand-alone tape drive when creating a full backup" option fails in some cases.

Known issues

This section describes issues that are currently known and provides solutions to avoid the issues where possible.

Installation and upgrade

  • [ABR-325252] Agent for Hyper-V cannot be re-registered on the management server via "Devices" → "Add" if it was successfully installed and removed before.

    Solution: restart the Acronis services on the agent before registration attempt.

  • [ABR-312731] Chain upgrade sequence, such as Acronis Cyber Backup 12.5 Update 5 → Acronis Cyber Protect 15 → Acronis Cyber Protect 15 Update 1 fails with "Error 0x430023: It is forbidden to use ''`"&?*$<>;\/#{}' symbols in names." error if the tape pool contains special symbols in its name.
  • [ABR-218875] When Acronis Cyber Protect 15 is uninstalled without using "Remove the logs and configuration settings" option and installed under new user, then new backup plans creation would fail with "Windows error: (0x80070005) Access is denied" error

    Solution: Uninstall Acronis Cyber Protect 15 without using "Remove the logs and configuration settings" option and install specifying the same existing user account which was used for the 1st initial installation.

  • [ABR-217534] When the backup agent is installed using HTTP proxy it still requires that the hostnames of Acronis Cloud servers (for example "") are resolved properly from the agent side, even if DNS redirection is set up within the proxy server.
  • [ABR-144289] Deployment of Acronis Cyber Protect Backup Appliance (All-in-One) from OVF template onto ESXi hosts versions 5.1 or lower produces VM with wrong guest OS type: "Other (32-bit)" which causes appliance malfunction.

    Solution: Change the guest OS type of the appliance VM to "Other 3.x or later Linux (64-bit)" via vSphere client.

  • [ABR-143693] Deployment of Acronis Cyber Protect Backup Appliance (All-in-One) from OVF template does not work when using vSphere Web Client on vCenter version 6.5 U1 build 5973321, since this version of vCenter does not support deployment from OVF templates (only OVA format is supported)

    Solution: Prepare the virtual machine for Acronis Backup appliance installation manually as described in documentation and boot it from Acronis Backup appliance ISO to proceed with the installation.

  • [ABR-142841] Acronis Cyber Protect Backup Appliance (All-in-One) ISO cannot boot on EFI systems

    Solution: use BIOS systems.

  • [ABR-142560] Deployment of Acronis Cyber Protect Backup Appliance (All-in-One) from OVF template does not work when using vSphere Host Client on ESXi version 6.5 with error: "A required disk image was missing"

    Solution: Either perform OVF deployment using vSphere Web Client instead of vSphere Host Client OR prepare the virtual machine for Acronis Cyber Protect Backup Appliance (All-in-One) installation manually as described in documentation and boot it from Acronis Cyber Protect Backup Appliance (All-in-One) ISO to proceed with the installation.

  • [ABR-131165] Simultaneous upgrade of multiple Virtual Appliances in the backup console is not possible.

    Solution: update Virtual Appliances one by one.

  • [ABR-130409] A machine may not appear on the Devices tab after Acronis Backup agent installation if the Acronis Backup Management Server host name cannot be resolved to IP from the machine where the agent is installed. The following error message appears in the installation log: "Could not resolve host: [HOSTNAME]; Host not found".

    Solution: When deploying an agent to a machine use the new GUI option to define the management server registration address which will be used by the agent (host name or IP). Alternatively ensure that the management server is accessible by its host name from the machine with the agent.

  • [ABR-130294] Updating or upgrading Agent for VMware (Virtual Appliance) that was encrypted by using vSphere 6.5 encryption fails. The following error appears: "An encrypted virtual disk device requires an encrypted virtual machine."

    Solution: Decrypt the appliance before update or upgrade.

  • [ABR-118182] In some cases, installation may hang at 96% for an period of time up to 10-20 minutes because of the Microsoft.VC90.CRT runtime package installation. The main symptom is the Windows Modules Installer (TiWorker.exe) process constantly consuming CPU resources.


  • [PLTFRM-18969] It is not possible to protect Microsoft SQL on a machine with a workstation operating system, in the case Agent for Hyper-V is also installed among local agents.
  • [ABR-279757] Applying a protection plan to Agent for Windows installed on Windows Server 2008 (32 bit) always fails.
  • [ABR-255521] The number of total runs and successful runs is zero for the Microsoft Office 365 resources.
  • [ABR-228827] If some backup is removed via the Data Recovery (Web Restore) console, this change is not reflected in the service console while browsing the backup location, until the service console is refreshed.
  • [ABR-207057] Bulgarian language is unavailable in Acronis Bootable Media for MAC.
  • [ABR-196710] The backup location on the network share usage is duplicated in the case when there is a different network share with the same name registered as a backup location (shares rotation scenario).
  • [ABR-189620] The "Activities summary" widget shows activities out of the defined date "Range" scope (excessive activities may be shown).
  • [ABR-184900] Local backup usage is not reported for backups stored on a network share with enabled deduplication.
  • [ABR-183764] Local backup usage is not updated for all virtual machine backups after deleting and re-adding a network location.
  • [ABR-182313] Local backup usage size is duplicated after reconnecting a locally attached storage (LAS) to a new Agent for VMware (Virtual Appliance).
  • [ABR-178648] The installer does not remove/update old libraries if the previous update was interrupted.
  • [ABR-154655] The protection plan may have the "Backup succeeded" status, even if this plan is completed with warnings. Alerts and activities still show the proper status of the plan.
  • [ABR-133689] Acronis MMS fails to start on the latest version of CentOS 7 that uses the 3.10.0-514.21.2.el7.x86_64 kernel version, due to the specific kernel bug:
  • [ABR-128209] After unmounting a volume mounted from a backup in the read/write mode, a new recovery point is added, even if the mounted volume was not modified. The root cause is that Windows automatically discovers newly appeared volumes and applies metadata changes to them, which forces Acronis Backup 12.5 to preserve these changes in a new recovery point during unmounting.
  • [ABR-127363] The cleanup rule By total size of backups is not available in the backup console if the backup destination is Acronis Cloud Storage.
  • [ABR-121236] Exporting multiple plans from the Plans tab does not work.

    Solution: Export plans one by one.

  • [ABR-113452] If a machine was re-registered under a different account without revoking the existing protection plan from it, this plan may still continue to run unexpectedly.
  • [ABR-111624] When creating bootable media in OS X 10.8-10.10, Acronis components fail to start. The following error appears: "Code signature invalid."
  • [ABR-106790] The service console is not shown properly on mobile devices.
  • [ABR-68302] The backup replication progress is not properly displayed in the Status column on the Devices tab for the machine that performs the task.

Backup and recovery

  • [ABR-190404] It is not possible to recover from the Large Scale Recovery backup produced by the "LSR" tool if this backup is split into multiple separate files (multi-volume).
  • [ABR-183082] Recovery of a Linux machine having some volumes with the XFS file system completes with the "Failed to process the boot loader configuration." warning. The machine is bootable despite the warning.
  • [ABR-158677] "Intel(R) 82574L Gigabit Network Connection" NIC is not properly recognized by Windows 10 after recovery of an image to a VMware Workstation virtual machine by using the bootable media.
  • [ABR-141823] There are incorrect backup items in a protection plan after updating Mac OS X to 10.13 High Sierra with conversion from HFS+ to APFS (some backup items are missing).
  • [ABR-137886] Backing up Mac with Apple RAID configured fails with the "No volumes were found when processing the 'Fixed Volumes' template" error. Apple RAIDs are not supported.
  • [ABR-134234] For a folder that is a junction of another folder, any changes made to the contents of the original data (linked to this junction folder) are not backed up. The problem is not reproduced only when using the backup format v12.
  • [ABR-131204] When backing up to a USB flash drive on a machine running Mac OS X and by using the Version 12 backup format, the backup operation may fail.. The following error appears: "Enumerator returned empty archive."

    Solution: Re-create the backup plan, with the Backup options > Backup format option set to Version 11.

  • [ABR-129997] When creating a backup of a machine running macOS to a locally attached disk formatted in FAT32 or ExFAT, the backup might fail. The following error appears: "Operating system error: Resource temporarily unavailable."

    Solution: Format the disk with HFS+ and restart the backup.

  • [ABR-129075] When browsing a folder in a backup during the file-level recovery via the service console, some child folders may not appear in the list after sorting by type if the folder contains many elements. To show all items of the folders, you need to scroll down in order to load the entire content of a parent folder and perform sorting only after that.
  • [ABR-115270] The "[All Profiles Folder]" template in a file level backup does not support a custom profile path.
  • [ABR-87244] File-level recovery from a disk/volume backup of NTFS volumes with the enabled native deduplication does not work.

Acronis Storage Node, Acronis Storage and data catalog

IMPORTANT: Installation notes: Agent for Windows is always installed with Acronis Storage Node. The agent is required to browse the location contents.

  • [DF-1502] In rare cases Catalog may show duplicate machine entries while browsing, if Acronis Storage Node and Acronis Catalog service are installed on different machines
  • [DF-132] Recovery/Download of an item from catalog fails with "Unknown location: [name]" error after the backup location name was changed.
  • [ABR-144981] Direct backup or backups replication from backup format version 11 to Acronis Cyber Infrastructure (Acronis Backup Gateway) location does not work.
  • [ABR-143735] Backup locations on Acronis Cyber Infrastructure cannot be accessed from Acronis Backup bootable media GUI

    Solution: register the bootable media on the management server and browse backups from "Backups" tab by selecting bootable media as agent for browsing

  • [ABR-128626] Data catalog cannot be enabled for managed locations created on tape devices.


  • [ABR-327505] Changed Block Tracking is not used properly when performing conversion into VM on Scale Computing HC3, which results in longer conversion process.
  • [ABR-320237] Debian 10 EFI VM with enabled Secure Boot is not bootable after recovery of backup captured from VMware ESXi to VM on Scale Computing HC3.

    Solution: Disable Secure Boot in the EFI boot manager configuration after recovery.

  • [ABR-320149] Recovery of backup for machine which contains a mix of IDE and SCSI drives, to Scale Computing VM, produces a VM which misses 1 disk (non-system SCSI disk is not restored).
  • [ABR-307522] Assigning a Virtual Host license to "FreeESXi" item fails with "Not all resources can be resolved" error.

    Solution: Use the licensing assignment method described in

  • [ABR-272002] Backup of a VM replica created using native Scale Computing HC3 VM replication feature, always fails.
  • [ABR-280084] The second incremental conversion of a backup into Hyper-V VM fails with error "Failed to read data from disk" when the target VM storage is on CSV.
  • [ABR-279222] The validation of a backup by running it as a VM on an ESXi host fails with error "You do not have access rights to this file".
  • [ABR-242166] An application-aware backup of a Hyper-V virtual machine may fail when executing the WMI query, with the "WMI 'ExecQuery' failed executing query." or "Failed to create a new process via WMI" errors, when the backup is performed on a host under a high load, due to no response from WMI.
  • [ABR-234935] There are duplicated activities in the Activities summary, after the backup of a virtual machine running on a Hyper-V cluster.
  • [ABR-234935] The number of email notifications is equal to the number of Hyper-V cluster nodes for one VM backup activity.
  • [ABR-214144] Locally Attached Storage (LAS) connected to Agent for VMware (Virtual Appliance) is available as target for VM files (.vhdx/.vmdk) generated by "Convert to VM" feature, while it should not.
  • [ABR-206940] Backing up a Hyper-V virtual machine located on a CSV volume may block moving this CSV volume to a different Hyper-V node, in some cases.
  • [ABR-206645] Backup of Hyper-V VM which has PMEM disk attached fails with "Error occurred during a request for the parameter" error.
  • [ABR-204800] Direct SAN Access (LAN-free) mode does not work when Agent for VMware (Windows) is running on Windows Server 2019 and the agent is managing vSphere 6.7 U1 environment
  • [ABR-192213] VMware virtual machines with an empty "vc.uuid" (InstanceUUID) vSphere property are not listed in the service console.
  • [ABR-189882] Backup of a Hyper-V VM fails with "Failed to get the disk information." error if the virtual disk has an ampersand symbol in the .VHD file name.

    Solution: fix the .VHD file name by removing the associated virtual disk from VM configuration and re-adding it after renaming

  • [ABR-173002] Run VM from a backup on a Hyper-V host fails, if the backup is located on the same volume as the path selected for the mounted VM disks. Solution: select a different volume for the mounted VM disks path. The space will be consumed only for changes generated inside the mounted VM and it will not occupy the entire size of the virtual disk.
  • [ABR-169367] Backup of ESXi VM template using SAN hardware snapshots fails with "Failed to get the used disk areas on the storage. There is no snapshot for the virtual machine disk" error.

    Solution: Disable "SAN hardware snapshots" option in Backup Options

  • [ABR-144733 + ABR-235983] Agentless backup of Linux VMs any "Policy rules" except "[Disk #]", for example such as "/dev/sda1", does not work.

    Solution: Perform Entire Machine backup or use [Disk #] policy rules.

  • [ABR-137883] Recovery of a Gen2 Hyper-V VM with enabled Secure boot option into original location finishes with warning: "Secure Boot has been disabled in the recovered virtual machine. If required, enable it manually.". Disabling Secure boot during recovery is done intentionally to guarantee proper VM boot up.

    Solution: follow the recommendation described in the warning.

  • [ABR-137564] Cross-platform recoveries (when the backup was created not by Agent for Hyper-V) into a new Hyper-V virtual machine by Agent for Hyper-V always produces the Gen 1 version of virtual machine.
  • [ABR-133681] A backup of an ESXi virtual machine fails if all of the following conditions are met: the backup is performed by Agent for VMware (Windows), the agent is installed in a non-English Windows, and Acronis Managed Machine Service is running under a system account whose name is localized. The following error appears: "You do not have access rights to this file."

    Solution: Uninstall Agent for VMware (Windows) and install it again. Set the user for Acronis services to some existing user or use the Create new user option instead of the default one.

  • [ABR-126058] ESXi host devices cannot be added to a group: the Add to group command is unavailable.
  • [ABR-125426] Canceling a running activity, like a virtual machine recovery, validation plan execution, or replication plan execution may fail. The following error appears: "An activity with ID = '[ID]' cannot be found."
  • [ABR-121704; ABR-90170] The backup percentage status in the Status column on the Devices tab may show invalid percentage (>100%) when backing up more than one virtual machine in a single backup plan and when the backup is performed by Agent for VMware (Windows).
  • [ABR-120840] ESXi host configuration backups ignore the GFS and Custom backup schemes selected in the backup plan. As a result, full backups are created instead of incremental and differential ones.
  • [ABR-118715] VMware vSphere virtual machine backup may fail if names of the ESXi hosts registered in vCenter cannot be resolved to IP addresses by Acronis Backup agent (Virtual Appliance or Windows agent), even if the vCenter host name can be resolved properly. The following error appears: "You do not have access rights to this file."

    Solution: Configure network settings at the Acronis Backup agent, by configuring the DNS or modifying the /etc/hosts file, to allow name resolution to work properly. To verify if the ESXi host can be resolved, run the following command on the machine with the backup agent: ping <ESXi host name>.

  • [ABR-104081] A VM replication plan execution may fail in unstable network environments even if the "Error handling" option is enabled.
  • [ABR-100551] Backup of a Linux virtual machine running on Hyper-V 2019 always fails over to crash-consistent snapshots, due to a Microsoft limitation (inability to create production checkpoints for Linux virtual machines).
  • [ABR-96496] Acronis Backup Agent for VMware (Windows) disables Windows NFS server functions when installed on Windows Server 2012, due to the ports conflict.

    Solution: Deploy Agent for VMware (Virtual Appliance) to the target ESX host or install Agent for VMware (Windows) on another machine with the NFS server functionality disabled.

  • [ABR-85645] Backup of a virtual machine with Active Directory may complete with warning "MFT bitmap is corrupted."

Tape management

  • [ABR-129546] Recovery points in tape-based locations do not appear for the protected machines on the Recovery tab in the Devices list) if the tape database was lost and a rescan operation was performed.

    Solution: Browse the backups on tapes by using the Backups tab of the backup console interface.

  • [ABR-123328] The backup option Use a separate tape set for each: Backup type is not activated by default during the backup plan creation, if the user first chooses the GFS backup scheme, and then selects the tape destination.

    Solution: Enable this option manually in Backup options.

Application support

  • [ABR-162925] Application items (databases and/or mailboxes) cannot be recovered from the application-aware entire machine backup if the databases are located on mount points (the database path is redirected to another location).
  • [ABR-122309; ABR-127970] The information about application items is missing from the data catalog.
  • [ABR-120853] Recovering Microsoft Exchange 2007 mailboxes fails if the target Microsoft Exchange version is 2010 or higher. The following error appears: "An invalid type of the target URI."
  • [ABR-74984] The "Next backup" time is not displayed for a machine that has only application-level protection plans applied to it.