#1 Global Leader in Data Resilience

Guest OS File restore fails with ‘The revision level is unknown’

KB ID: 2776
Product: Veeam Backup & Replication | 9.5 | 10 | 11 | 12 | 12.1 | 12.2 | 12.3
Published: 2018-09-26
Last Modified: 2021-11-09
mailbox
Get weekly article updates
By subscribing, you are agreeing to have your personal information managed in accordance with the terms of Veeam's Privacy Notice.
This site is protected by hCaptcha and its Privacy Policy and Terms of Service apply except as noted in our Privacy Policy.

Cheers for trusting us with the spot in your mailbox!

Now you’re less likely to miss what’s been brewing in our knowledge base with this weekly digest

error icon

Oops! Something went wrong.

Please, try again later.

Challenge

When attempting to restore files from a backup of a server that was running Windows 2016 (or 2019) and had Deduplication enabled for some (or all) of the drives, the restore fails with the following error:
Failed to restore "<filepath>" Error: Failed to read xx bytes from the file [\\?\C:\VeeamFLR\<vmname>\Volume#\<filename>] in async mode. 
Win32 error: The revision level is unknown. Code: 1305
Navigating to the location shown in the error on the Mount Server, the file can be seen, but it cannot be copied. Attempting to copy and paste it another location causes the error:
Error 0x80070519: The revision level is unknown.

Cause

Experiencing this error means that the Mount Server has the required Deduplication role enabled, but the OS of the Mount Server is older than the OS of the VM that was backed up.

The OS requirement is also noted in the warning message that pops up as the Backup Browser opens after the restore is initiated.

Copying and restoring files from deduplicated volumes requires that the mount server associated with the source backup repository uses the same or later guest OS version.
Pop warning states Copying and restoring files from deduplicated volumes requires that the mount server associated with the source backup repository uses the same or later guest OS version.

Solution

To resolve this error, the mount server associated with the source backup repository must be using the same or later guest OS version as the VM that was backed up. Either (a) select a different Mount Server running the same or newer OS than the VM that was backed up, or (b) upgrade the existing Mount Server's OS.

 

More Information

To submit feedback regarding this article, please click this link: Send Article Feedback
To report a typo on this page, highlight the typo with your mouse and press CTRL + Enter.

Spelling error in text

This site is protected by hCaptcha and its Privacy Policy and Terms of Service apply except as noted in our Privacy Policy.
Thank you!

Thank you!

Your feedback has been received and will be reviewed.

Oops! Something went wrong.

Please, try again later.

You have selected too large block!

Please try select less.

KB Feedback/Suggestion

This form is only for KB Feedback/Suggestions, if you need help with the software open a support case

By submitting, you are agreeing to have your personal information managed in accordance with the terms of Veeam's Privacy Notice.
This site is protected by hCaptcha and its Privacy Policy and Terms of Service apply except as noted in our Privacy Policy.
Verify your email to continue your product download
We've sent a verification code to:
  • Incorrect verification code. Please try again.
An email with a verification code was just sent to
Didn't receive the code? Click to resend in sec
Didn't receive the code? Click to resend
Thank you!

Thank you!

Your feedback has been received and will be reviewed.

error icon

Oops! Something went wrong.

Please, try again later.