Any solutions for this issue so far? We're having the same problem, and the latest document I found was Document 315447 which simply says, there is no solution for it.

I don't think there's a solution yet :-(

Rich

I just started experiencing on one VM.  Did anyone ever find resolution?

Steve

 I've got the same problem.
I installed BE 12.5 with AVVI and i ran about 50 test job on all my VmWare vsphere virtual machine.
Sometimes everything work's fine, sometimes i get 50% fine and the other getting the "Failed to mount one or more virtual disk images" message, sometimes all of the VM gets the error message.
Without any relationship!!!!
I've got 3 windows 2008 x64, 2 windows 2008 x86, 4 win 2003 x86 and one 2003 x64. 

The BE Server is win 2008 x64 SP2 with vcb framework and Converter installed, Updated with live update, remote agent on every server pushed after the BE update, removed the vmware vss provider from the VM, installed the BE VSS Provider, configured the freeze.bat script, disabled the sync driver in every VM.
I found few docs in the Symantec knowledge base but no one apply in my environment.
I'm driving crazy with this problem.

Hey Man, you're not alone I also having the same problem here of cannot mount Virtual disk ?

any progress on your case ? perhaps you can share it here please ?

Thanks.

Are all the updates to BE 12.5 applied, by using liveupdate, there have been hotfixes in the past to fix this issue, if it is speciifically a utility partition or extended volume on the vmware disks. Make sure all the patches are applied and then test a backup.

Thanks

 I applied every patch available and update all the remote agents, but the error persist...

This version of backup exec disappoint me day after day... a lot of issues with no solution....

 And I have no utility partition in any of my servers.
Everytime i ran the backup process the "failed to mount..." error messages is related to a different server, apparently with no logic.