Exchange 2013 CU11 broke backups

[jwsconsult]

I installed Cumulative Update 11 on Exchange 2013 for a client a few weeksa go, and since that time, he has not been able to backup the mailbox databases on his server.  When previously working backup runs, he gets error V79-57344-913 saying that BE cannot find a healthy copy of the Exchange database.  Also, if I try to modify the selection and choose the databases, I get a credentials denied error.

Here is what I have tried so far to fix the issue

Added registry key for PowerShellOptions set to 1, per KB to fix Mailbox Anchoring in Exchange 2013 CU11/Exchange 2016 CU1. 

Updated backup server and remote agent to Backup Exec 15 FP3

Changed credentials on backup job and Backup Exec Remote Agent to an account with Domain Admin (in AD) and Organization Management (in Exchange) permissions, again, per KB.

Despite this, the backups are still returning the same error.  Any guidance I can get on this would be greatly appreciated.

Thanks!

Joel

[CraigV]

Have you tried:

1. A repair of the BEDB?

2. A repair of the BE installation itself?

Thanks!

[VJware]

Have you tried recreating the backup job ?

Also, try granting these minimal permissions - https://www.veritas.com/support/en_US/article.TECH212113

[jwsconsult]

VJware.  A new backup gives the same error on trying to browse/expand the information stores, even after applying permissions in the document.

Craigv, I ahve not tried either of those yet (and a backup is running now so I can't do either), but I don't believe eithera re the issue, as backups of other servers are still running fine, and even backups of the actual filesystem on this server are running fine.  The only issue is the mailbox databases, and it has only happened since installing CU11.

[jwsconsult · Accepted solution]

It appears that a complete uninstall and reinstall of the agent (BE 15 FP3) fixed the issue.  Backup is at 1.53GB now, it previously was failing immediately.

Cheers