The following message is seen during backup.
ANS1071E Invalid domain name entered:
Resolving the problem
It is possible that other applications may make a snapshot as part of their backup process that will appear as though it is a volume on the OS. This can cause Tivoli Storage Manager to try to back it up. However since it is not a real volume, the ANS1071E Invalid domain message is seen.
Review the Windows application event log for other applications that are making snapshots of the filesystem at the same time the client backup is occurring.
Once identified, the backups should be scheduled so that they are not running at the same time.