When contacting Acronis Support with a technical issue, it is recommended to have Acronis System Information at hand


Backup of a Windows machine fails with error:
Logon failure: unknown user name or bad password.


Acronis Cyber Backup agent receives this error from Windows while trying to access backup source or target.

This article describes how to use Web Restore to retrieve files or folders without using Acronis software.

You restore a machine to dissimilar hardware and apply Acronis Universal Restore.

The process completes successfully, but the restored machine goes to BSoD with error "Stop 0x0000007B".


You get errors when you use Acronis software to connect to  a mailbox or public folder via the Exchange Web Services (EWS) protocol.


To verify if an error is related to Acronis software or to the environment, you can use a tool called EWSEditor to connect to the mailbox or public folder that causes errors and check if the error appears. This can be very useful in scenarios when:


User wants to manually delete a .tib/.tibx backup archive in Explorer, or to modify Acronis configuration files, e.g. to adjust settings of alerts or change default ports for services.

Operation fails with “Access denied” error:

Folder access denied
You need permission to perform this action


Access to Acronis files may be denied by Acronis Self-Protection.


  1. You try to install Acronis Backup on your Debian machine.
  2. You cannot install neither 64-bit version, nor 32-bit version of Acronis Backup.
  3. Installation fails with :

    Please use installer compatible with x86_64 OS.


You try to install Acronis Cyber Backup 12.5 or Acronis Cyber Protect 15 on a machine where a NIC is disconnected or missing. Both Management Server and Agent are selected for installation.

At 99% of installation progress you get an error:

Registration failed.

Backup agent: "Failed to connect to the management server"

Manual registration fails with an error: ZmqGW return empty AMS addresses list


Issue in the product.


You created a WinPE-based bootable media.

When you boot a machine with Windows 8 or later, or Windows Server 2012 or later with this bootable media, Disk Management option is missing. 


This is the expected behavior.

WinPE-based media supports Disk Management utility for Windows 7 and below. Disk management for Windows 8 and 10, and Windows Server 2012 or later is not supported in WinPE of Acronis Cyber Backup 12.5 and Acronis Cyber Protect 15.


  1. You want to update several Hyper-V agents at once under Settings - Agents,
  2. When you select required agent machines, the following error is displayed:

More than one Agent for Hyper-V is selected. Simultaneous update of multiple Agents for Hyper-V is not possible. Please update these agents one by one.

You install Acronis Agent on a Linux machine. Installation completes with this error:

Failed to build the SnapAPI kernel module. Operations with disk-level backups will not be available.


You have installed Acronis Cyber Protect 15 software and attempt to deploy Agent for Scale Computing HC3 (Virtual Appliance);

Deployment of the Agent for Scale Computing HC3 (Virtual Appliance) instantly fails with the following error:

Failed to download the virtual appliance. Check the Internet connection on host <hostname> or download the file...


  1. When you try to manage licenses in Settings > Licenses, nothing happens. The interface just blinks, and the license is not assigned or revoked. No error message is shown. 
  2. Protection plans are executed as if the licenses were assigned correctly.
  3. In the account_server.log (located in \ProgramData\Acronis\AccountServer\Logs), you see error messages similar to the following one:


The P2V migration or V2P migration of the machines with LVM can be performed only if the backup was created using the agent installed inside the virtual machine (or on physical machine) and the restore operation should be performed using Acronis Bootable Media.

If a machine has LVM volumes, keep in mind the following limitations for restoring to a different platform:

  1. You create a backup using Version 12 format.
  2. An operation with archive (e.g. applying retention rules) fails with the error message

    Failed to lock the file


  • You have upgraded your system from Acronis Cyber Backup 12.5 to Acronis Cyber Protect 15. 
  • After the upgrade, you created new protection plans. When you try to edit a newly created protection plan, there is a spinning loading circle with Reconnecting... message.

This article applies to:

  • All Acronis software


  1. You are installing Acronis software in Windows
  2. Installation fails with:
    The Windows Installer Service could not be accessed. This can occur if the Windows Installer is not correctly installed. Contact your support personnel for assistance.


Issue in the Windows Installer.

You have upgraded from Acronis Backup Advanced 12.5 Update 5 (build 16386) to Acronis Backup Advanced 15.

After each reboot, you get multiple alerts:

Cyber Protection (or Active Protection) service is not responding


After agent update to Build 24600 or 24476, Acronis Scheduler randomly generates errors in Windows Event log:

Scheduler failed to run task with GUID '15C608E6-C6BD-4C21-B41C-E10368FDACD8' because of error 2 (Failed to find the file (folder) or the key (value) in the registry.)

GUID is different on each device.


Issue in the product. Obsolete service tasks are not deleted automatically during update.


This issue is fixed in Build 26172, please update to the latest build.

After a recent Cyber Protection definitions update, word.exe cannot be opened on the agent machine. It does not start even when Acronis services are disabled or when word.exe is added to Exclusions.


  1. You want to install an agent in an environment with a proxy.
  2. You have configured proxy according to the user guide (Acronis Cyber Protect 15
  3. Agent registration fails with the following error:

    503 service unavailable

Cleanup Utility is a console application that removes all Acronis products and their components from Windows.

(!) Cleanup Utility should be used only in case the product fails to be uninstalled the usual way from Windows Control Panel or using the installation file.


Symptoms depend on the product version:

  • Acronis Cyber Backup 12.5 builds 16180, 16318, 16327, 16342, 16343 contain build 0.7.127 –  SnapAPI module will not compile on kernel 5.8 and later
  • Acronis Cyber Protect 15 builds 24426, 24508, 24515 and later contain SnapAPI build 0.7.133 which imminently leads to kernel crash and the following error: 

cannot execute binary file: Exec format error
when trying to execute any binary file.


Activity fails with:

Windows error: (0x800704C8) The requested operation cannot be performed on a file with a user-mapped section open


You try to access the protection console by entering the login page address into the web browser address bar or by clicking on Acronis Cyber Backup shortcut.

After you specify the required credentials, web browser does not connect to Management Console. Possible errors are:


  1. You have set up some Agents for VMware (Windows or Virtual Appliance) connected to a vCenter/ESX(i) host.
  2. Some virtual machines do not appear in Cyber Protection console after recovery or physical to virtual conversion


Current Acronis Cyber Protect products use VMware "InstanceUUID" property in order to identify each virtual machine. If one or more machines use the same InstanceUUID then only one machine will appear in the console.


  1. vCenter/ESX(i) ホストに接続されている一つまたは複数のエージェント for VMware(Windows あるいは仮想アプライアンス)をインストールしました。
  2. 復元あるいは物理から仮想への変換の後、すべてあるいは一部の仮想コンピュータは Cyber Protection コンソールで表所されていません。


現在の Acronis Cyber Backup 製品は、仮想コンピュータを識別するために、VMware の「InstanceUUID」プロパティを使用します。1台または複数のコンピュータで同じ InstanceUUID が使われている場合、コンソールでは1台のみ表示されます。

より古いバージョンからアップグレードされている Acronis 製品では、仮想コンピュータの識別のために BIOS UUID が使用されている場合があります。その場合、識別方法を BIOS UUID から InstanceUUID に変更できます(この記事の説明に従ってください)。