For the past almost 6 years, this setup has worked and just recently has it stopped. I've got BE 15 installed on a Server 2012 machine, with agent on 3 other server 2012 machines. Backing up to tap...
You are right. That appears to be the problem. The size of the backup has remained steady over the years, but the tapes we have are very old. Do you think they just need to be replaced?