Acronis Backup Cloud Known Solutions

Your Acronis Backup Cloud quick troubleshooting kit. Below are the most recently published and the most popular articles. The solution you are looking for is most probably right here.

Most recent articles

Application-aware backup fails on newly installed SQL instance with "Account does not have enough privileges to access instance"

You have an application-aware backup of an SQL instance.

After a while, you add another SQL instance to your SQL server.

Backup completes with warning, second instance is not backed up:

2019-03-26T13:20:05:728+03:00 2236 W02140000: service_process(2976): Failed to save the metadata for group 'mssql://INSTANCETWO/DB_ONE'. Reason: 'Error 0x571102: Cannot back up SQL Server database 'DB_ONE' of instance 'INSTANCETWO'.
| line: 0xec865955c73bb297
| file: e:\301\enterprise\applications\mssql\aavb\addon\src\aavb_progress_control.cpp:62
| function: MsSql::AavbProgressControl::OnDatabaseError
| $module: aavb_mssql_backuper_vsa64_12420
| error 0x570133: Account '' does not have enough privileges to access instance 'INSTANCETWO'. To be able to back up or recover the instance, the account must have the SQL Server sysadmin role in it.
| line: 0xa590150b0bc6beec
| file: e:\301\enterprise\applications\mssql\common\src\online_mssql_server_information.cpp:1213
| function: `anonymous-namespace'::OnlineInformationBuilder::CollectMetaWithOdbc
| $module: aavb_mssql_backuper_vsa64_12420'.

Backup fails with "The specified file does not exist"


Backup in Version 12 format fails with following error message:
error 0x40011: The specified file does not exist

Backups in Archive11 format write excessive .meta files to temp

You create backups in Version 11 backup format. You notice, that large (up to several GB) .meta files are written into the %temp% folder.


You have Acronis Agent for Hyper-V installed on Windows Server 2019.

In Windows Event logs, you see multiple errors with Event ID 81:

Logging in to Web Restore fails wih "504 Gateway Time-out" for large accounts

You have a account with a vast number of machines (several hundreds). You log in to the Web Restore console.

Login fails with:
504 Gateway Time-out


Office 365 backup fails with:

CODE O365MailboxPrimaryMbxBackupError
MESSAGE Cannot back up the primary mailbox of an Office 365 user: 'folder: mailbox primary root: token validation failed'


Required permissions have been revoked from Acronis Agent in Office 365.


Re-register Office 365 account:

Office 365 backups still run after being revoked

Previously, you had Acronis Agent for Office 365 installed on the machine and performing backups. Now you use the cloud Agent and have revoked all plans from the old local agent. However, you get this error:

Error code: 113
Module: 307
LineInfo: 0xC37471CEFFA1827A
Fields: {"$module":"agent_protection_addon_vsa64_12420"}
Message: Selected Microsoft Exchange mailboxes were not found: Mailbox with ID 'arx://is/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX'
Mailbox with ID 'arx://'
Mailbox with ID 'arx://'

Live update does not start
  1. In the backup management console, you notice that a new product build is available and click Update to start installation.
  2. Message "Updating" is shown for about 30 minutes, but update does not happen.
Device does not appear in backup management console after installation

You have installed Acronis Agent and registered it in your account, but when you open the backup management console, this device is not listed in Devices.

In mms log on the affected machine (located in C:\ProgramData\Acronis\BackupAndRecovery\MMS\), you see this error:

| error 0x1403f4: WMI 'ExecQuery' failed for query '%ls'.
| line: 0xc523d9a02d03d55c
| file: e:\310\core\winex\wmi_acc.cpp:305
| function: Windows::WMIClass::Select
| Query: SELECT * FROM Win32_OperatingSystem
| $module: mms_vs_12420

Linux bootable media fails with "Kernel panic - VFS: Unable to mount root fs on unknow-block(1,0)"

You downloaded the bootable media to use it for recovery. You create an empty VM and start it with the ISO image. 

You receive this error:
Unable to load initial ramdisk.

After pressing Enter, you receive this error:

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(1,0)


Most viewed articles

"Failed to Connect to the Process" error

You may get the error as a result of exceeded timeout for disk system initialization. Disk system initialization is executed during backup. To fix it, add a value StartTimeout in Windows registry.

"The shadow copy provider had an unexpected error while trying to process the specified operation"

VSS-Backup fails with "The shadow copy provider had an unexpected error while trying to process the specified operation". To solve this issue, troubleshoot the VSS provider mentioned in the message.

"Backup failed" alert

A backup did not complete successfully.

"Failed to read the snapshot"

You attempt to perform a disk or partition backup that fails with the following error: "Failed to read the snapshot."

Linux-based bootable media does not support PERC RAID controllers

The RAID array is seen as separate drives

"Backup finished with warning", "Activity finished with warning", "Activity failed" alerts

An operation in Acronis Backup 12.5/12, Acronis Backup Cloud, or a customized backup solution based on Acronis Backup Cloud finished with a warning message or failed.

"Backup did not start" alert

This alert is displayed when our product detects that a backup activity was not started at the scheduled time. For example, if a machine was turned off during scheduled backup time, this alert will be displayed the next time it is connected to the Management Server. 

Machine is offline in Backup Management Console

After successful installation, the machine is offline in the Backup management console.

"Backup status is unknown" alert

This alert appears when the agent machine is offline during a scheduled backup. In this case, our Management Server has not received information whether the backup is running successfully or failed.

"VSS writer 'SqlServerWriter' with class ID 'A65FAA63-5EA8-4EBC-9DBD-A0C4DB26912A' has failed to process the snapshot"


Backup fails with the following message:

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