Hello!

Have you followed the documentation to make sure the account you’re using to interact with the server has the relevant SQL Server permissions on this instance?

Yes I did.
And the warning error started only today, the backup was successful with warning for few days.

Hi @Nourinux ,

have you verified corresponding SQL logs in the event viewer?

Do you have AAIP enabled in your job for SQL?  Check the logs here for the backup job name to see if that gives you more details - C:\ProgramData\Veeam\Backup

Yes enabled.

What keyword are we looking for in the logs?

Error or warning. Look for lines about truncation.

Please refer to the KB https://www.veeam.com/kb2027. 

Thanks!
But it didn’t solve the issue.
I opened a case about it, the support team is checking the logs and figuring out the root of the issue.

May be this: 1 new message (stephenwagner.com)

Petr

This is a very good article if it pertains to your issue.  I would check it out.