Instructions on how to enable Microsoft native VSS instead of the default Acronis VSS in Acronis Backup & Recovery 10

Make sure the backup is run under administrator or that you back up without using VSS

Installation of Acronis Product fails with SnapVssProvider Error in MSI log. This article provides information on how to find, identify and resolve typical errors in MSI logs of Acronis software.

Compatibility issue of Acronis True Image with NTBackup

You either have 1) Windows Server 2008 R2, or 2) Windows Small Business Server 2011, or 3) EFI system partition, or 4) EISA service partition

Instructions on how to enable Microsoft native VSS instead of the default Acronis VSS in Acronis Backup

You are running a single-pass backup of SQL instances that fails with the error. To fix this issue, re-register the VSS service

Acronis VSS provider is used to initiate creation of VSS snapshot, but MS VSS service is actually used

The reason is that the backup was created with disabled VSS support

Unlock the partition using diskpart

Backup on Windows XP fails with error "Failed to create volume snapshot" if MS SQL Server is installed.

The “File Server VSS Agent Service” role service must be enabled on the file server hosting SMB3.0 share.

This article applies to:


Backup activity fails with the following error:

Operating system error: The shadow copy provider had an error. Check the System and Application event logs for more information.

You are protecting Windows Server 2008 R2 with Acronis software.

Backup fails with the following error messages:

Error code: 1098825
Fields: {"$ module": "disk_bundle_vsa64_xxxxx"}
Message: Locking of volume snapshot failed.
Error code: 9
Fields: {"$ module": "disk_bundle_vsa64_xxxxx", "code": 3758096391}
Message: Already blocked.

While checking VSS doctor report or Windows Application Event log you find the following (or quite similar):

Volume Shadow Copy Service error: Unexpected error calling routine RegOpenKeyExW (-2147483646, SYSTEM \ CurrentControlSet \ Services \ VSS \ Diag, ...). hr = 0x80070005, access denied.

You are protecting Windows Small Business Server 2011 Standard.

When checking VSS doctor report or Windows Application Event log you found the following (or similar) warning for "spsearch account" and 1376 status code:

Type: Warning
Source: VSS
Message: Volume Shadow Copy Service error: Unable to resolve spsearch account with status 1376. Check connection to domain controller and VssAccessControl registry key. Operation: Collecting Write Process Data Asynchronous Operation Execution Context: Execution Context: Requestor Current Status: GatherWriterMetadata Error Details: Error: NetLocalGroupGetMemebers (spsearch), 0x80070560, The specified local group does not exist.
InstanceId: 8230
SearchLink: https://www.google.com/#newwindow=1&q=VSS+event+id+8230

Recovery of MS Exchange database/storage group fails if committed transaction log is missing in the backup


Application-aware backup fails with one of these errors:

Error 1

Error code: 34865165
Fields: {"$module":"aavb_backup_command_addon_vsa64_23140"}
Message: Failed to get the metadata from the 'VMware Snapshot Provider' extension library.
Error code: 65520
Fields: {"$module":"aavb_backup_command_addon_vsa64_23140","code":2147942402}
Message: The system cannot find the file specified


Disk/partition backup fails with: 

Windows error: (0x80070001) Incorrect function


Acronis Cyber Protect Home Office and Acronis True Image support VSS-aware databases for both disk-level and file-level backup.


You are installing Agent on a Windows 2003 or Windows 7 machine.

The installer shows the following warning:

The KB940349 update is not installed on this machine. Install this update to avoid disk backup failures


An outdated VSS version is installed on the machine. To guarantee correct backup functioning, we always recommend updating VSS components to the latest available versions.

This article applies to backups of Hyper-V VMs performed by Agent for Hyper-V (agent-less)



Prior to performing the backup, make sure that the below prerequisites are met:

1. Hyper-V Integration Services must be up-to-date and running inside the virtual machine(s).