Repeated failures of ATTIH2012 full image of disk

Attached is a portion of the log of a image backup listing the error I am getting. The settings for this backup has not been changed in six months. I was getting successful backups until a week ago. Now I get the the same error each backup. I make daily backups.
I have no idea what the error means or what to troubleshoot. Can you steer me in the correct direction?
I am using ATTIH 2012 with Plus Pack.