Backup Exec 2012 cannot change offline media description (solved)

This is a working solution to issue raised here http://www.symantec.com/connect/forums/backup-exec-2012-cannot-change-media-description 

Problem: 

"I noticed today that I cannot change media description of my tapes. When I try to change the description of the media the button Apply gets greyed out. Only the tapes that is online is possible to change the description of."

Workaround:

If tape is offline, assign it to any vault for a while (if you utilize vaults, create a fake one to avoid confusion). Media description change works fine for media that are either online, or assigned to a vault. Vault assignment can be removed once description has been applied.