This just started happening about 4 days ago. The backup job was running fine before. The C, D, and E would get this error and have 0 bytes backed up. The Utility partition, Shadow copy components also get this error. The System State gets backed up but has a message that says 'The .DR file that is required for IR is not updated'.
I'm assuming you are backing up a remote computer when this happens. Check to see if the Backup Exec Agent is crashing on that remote server. Check the event logs for any errors on the remote server and the media server.
I don't see anything on the event viewer about the BE agent crashing. The only BE services running now(without any backup job running) are the BEBDG and PDVFSService services.
I noticed that the remote server has a pending reboot due to a patch recently installed.