Just to follow up on this: I rolled the Domino server back to the 11D agent and it has successfully backed up four times now. I plan on testing the 12 SP1 agent this weekend to see if it is resolved...if not I will stick with 11D agent. Hope this he...
I'm experiencing this same error on my mail server and have been unable to consistently backup for weeks since upgrading to 12.. I use BESR to backup the c: and BEX to b2d c: and d:, then both go to tape. Mail server: Server 2003 R2 SP2, Domino 7.0...