At the direction of DI support, you may be asked to reset the Yosemite Catalog or ("version the database").
Before proceeding, please take a screenshot of the Devices/Slots view and confirm that you know what the contents of each tape in the loader are and what slot they are in.
From the Server-RM desktop, select Terminal (LXTerminal, Konsole, or GNome Terminal) and type the following:
1.) cd /usr/local/barracuda/yosemiteserverbackup
2.) service YTBackup stop
3.) mv database database.YYMMDD (where YYMMDD is the date)
4.) service YTBackup start
5.) exit (to return to the desktop)
After 2-3 minutes, open the Yosemite Server Backup application from the server desktop. Update the Domain Security: File --> Domain Config --> Domain Security, un-check "require password".
You'll note that there will be no backups defined and all tapes will be in an unknown state. You can then import a tape (or tape set) in order to access its contents.