Backup Exec jobs WERE working, migrated AD to 2012, failing

[agravanea]

2008 R2 DC was the only AD box in the joint. Added a 2012 server and migrated AD and roles to that. Still have Backup exec working and running same jobs from the 2008 server which is still in prod, just as a DC now. but suddenly some of the jobs from the one specific server are failing on the verification process of the daily backup for the NAS. 

Job Log: BEX_DCSERVER_04778.xml

Backup
V-79-57344-65149 - AOFO: Initialization failure on: "System?State". Advanced Open File Option used: ...
Snapshot provider error (0xE000FE7D): Access is denied.
To back up or restore System State, administrator privileges are required.
Check the Windows Event Viewer for details.

now i have used the credential section of the job to test all the creds and they all work. I have added a registry key to stop validation of creds to the reg per the forums here.
thought that would work, but nope. Still having an issue with that backup. from 2008 DC (which runs some stuff yet like fileshare etc and is still a DC), to the NAS. keeps failing.

any ideas? i have looked up the errors and called and found nothing that worked, and was rejected as out of support (2010) etc.

[pkh]

To backup a 2012 DC, the BE server needs to be on Windows 2012