DIAGNOSIS The door lock assembly (official name is door latch) has failed. The internal solenoid or microswitch is defective, so the control never receives the "door closed" signal.
FIX Replace the door latch assembly (part #WPW10705657). Unplug the machine. Open the door. Use a flathead screwdriver to pop off the plastic trim surrounding the door opening. Remove the screws holding the latch in place, disconnect the wiring harness, and install the new latch.
IF THAT DIDN'T WORK Check the wire harness between the door latch and the main control board for damage or a loose connection. A pinched or cut wire can cause the same symptom.
HEADS UP Never try to bypass the door lock. The washer will not operate without it for safety reasons. The control board will fault if it doesn't see the correct sequence of signals from the latch.