on an original DC Drive this error was caused by the CPU telling the Drive everything is ok to run. The brake opens and the M switch pulls in, then if it is an up call there would be no voltage to the motor brushes. The car would drift up due to the counterweights and throw a 45 error. If it was answering a down demand it would throw a comparator trip fault. If you can get control of the car by changing the B+ and B-, then try reversing the Armature A1 and A2 wires to the motor at the same time.