Parking rest app fails silently if no default parking lot set

Scenario, new PBX setup with parkpro and restapps. The initial setup involves creating extensions. Later you create parking lots. When created in this sequence, none of the extensions have a default parking lot.

When an extension uses the parking restapp button to park a live call, the phone does DTMF blind transfer to the default parking lot for the extension, i.e. ##70#. But if there is no default parking lot set for the extension, then the restapp just does DTMF ### and the transfer fails. There is no indication to the user what the problem is. Suggest that the park restapp display an error message or just blind transfer to the default parking lot for the system.