I received this error as well, for no particular reason that I could identify.  There were no template rules in the policy governing the backup in question.  I selected the job in the Job Monitor, clicked "Hold schedule", waited for the change to apply, and then reversed the change.  The job's status changed to "Scheduled" as I would expect.

I am also experiencing this problem. The only rule I normally use is 'supersede’ and then the status would show, 'superseded by xxx' although on this server, no rules were configured.