This is a Short-circuit fault or grounding fault at the drives output.
Suggested things to check :
-Disconnect the motor and Megger out the motor with 1000v Megger.
-Check all the cables connecting the drive and motor.
-Try running the drive with the motor disconnected to do so set OPL (FLt menu) to no and run the drive at 15, 30, 45 and 60 Hz and measure the output voltages with a digital RMS meter to see if all of the voltages are balanced.
-Replace the drive if needed.
-Replace the motor if needed.