DIAGNOSIS dE is a door lock error. The lid lock assembly (part DC64-02826A) is faulty. The latch mechanism or the solenoid inside it fails.
FIX Unplug the washer. Remove the two screws at the rear of the top panel. Slide the panel back and lift it off. You'll see the lock assembly on the underside of the cabinet top. Disconnect its wire harness. Remove the two screws holding it. Install the new lock. Reassemble.
IF THAT DIDN'T WORK Check the wire harness connection to the main control board. A bent or loose pin can cause the same error.
HEADS UP The washer will not agitate or spin without a confirmed lock. Never bypass the lid lock. The interlock is a critical safety feature.