Have you checked the wiring between terminals 63 and 64 on the brake and cpu boards? Do you have a service tool? If so clear all the faults.If not try clearing all the faults manually using the blue and white buttons. This is a brake fault, you may have a bad brake or cpu board also.
That being said, if you have the later 2.0 controller, the 83 is a motor overload fault. the 24vdc is missing on the main board terminal 37.