Unable to delete an assignment in Mainstage 3

I had mapped some assignments for a sustain pedal and then saved, closed, & re-opened Mainstage 3. One of the assignments I set showed a different mapping after opening Mainstage, and when I tried deleting it the mapping changed to ConcertName > Block so I'm unable to use any controls that are unmapped (pitch wheel, mod wheel, etc.) When I select this assignment, it won't let me edit or delete it.