I get this error every night on one of my remote servers I'm trying to backup.
AOFO: Initialization failure on: "Microsoft Information Store". Advanced Open File Option used: VERITAS Volume Snapshot Provider (VSP).
Snapshot provider error (0xE0008516): Resources specified for snapshot do not have any valid data on them. Check if files were deleted or renamed.
Check the Windows Event Viewer for details.
The backup server is 10.0 Rev. 5520 (yet I was also getting this error on the previous build)
I re pushed out the remote agent and AOFO agent to the server for 5520
The server that is erroring is: Windows 2000 Server (SP4), a Domain Controller, has Exchange 2000 (SP3), and SAV 9.0 Corporate Edition Server.