Diagnosis
The repeated clicking is the sound of the door lock's internal solenoid attempting to engage but failing to do so. This is almost always caused by a failed door lock assembly (part DD97-00645A is common for this model). The component contains a solenoid for latching and microswitches to signal the main control board that the door is secure; when one of these internal parts fails, you get the rapid clicking and the washer will not start its cycle.
How to Fix It
You must replace the faulty door lock assembly. First, unplug the washer. Open the door and remove the inner door boot seal's outer clamp. Peel the rubber boot back from the front frame to expose the metal door lock housing. Unplug the wire connector, remove the two Phillips-head screws securing the lock, and install the new assembly in reverse order. Ensure the boot is reseated properly in its channel before reinstalling the clamp to prevent leaks.
If That Didn't Work
If a new lock doesn't solve the issue, the problem lies elsewhere in the circuit. Inspect the wiring harness that runs from the door lock to the main control board for any pinched, frayed, or broken wires. Also, while rare, a failed main control board itself can send incorrect signals, preventing proper lock operation even with a new part installed.
Heads Up
Do not attempt to bypass or manually jam the door lock mechanism. The washer is designed to not fill with water, agitate, or spin unless it receives the correct secure signal. Bypassing it creates a serious flood risk and potential for injury during a high-speed spin cycle.