image cleanup partially succussful due to old clients removed

Netbackup 7.5.0.4 on Solaris 10.  After deleting an old policy for a server no longer online, my image cleanup is partially successful with the following error:

"Error nbdelete (pid=20502) Fragments were not removed. Server <client name> is invalid (37 )"

I removed the acutal client name due to security rules.

I encountered this issue several years ago, but do not remember the solution.  Thanks for any help.