You don't specify what version of Data Protector you are using, but, from your screenshot, it appears that the Protection on the Backup has expired, and the Catalog has been deleted, which is an Automatic Maintenance function
Your screenshot seems to indicate that the backup session was 2014/07/06-2, so run this command to see if it is still protected
omnidb -session 2014/07/08-2 -detail