I have a workspace I'm using in V12 Build 1507 that descended from V10.5 and I noticed that the "Backup successfully completed" message was always showing the same .zip file name, "\CPTee[1].zip". But that file was nowhere to be found.

Apparently it is possible to have an older workspace that when migrated to V12 won't backup to the location it was using in the prior version.

It is suggested after restoring a workspace backup into V12 that you go to the Control Panel then select "Tools / Backup Restore Workspace / Backup Workspace" and ensure you have a Drive AND a Folder specified.