This can be caused when the backup account used does not have sufficient permissions to log on as batch job.

Either

1. Add the backup account to the local administrators group on the server; or
   
   
2. Give the backup account Log On As Batch Job.
   As an administrator run Local Security Policy management console
   Go to Start Menu > Administrative Tools > Local Security Policy > Local Policies > User Rights Assignment > Log On As Batch Job and add the backup account