I just had the same error, I opened the back and the top cover, took out drain filter, it was so clean, we just got the house along with it two years ago. Anyway, the door was locked along with the errors, so next thing I went to look is the lock mechanism from the inside. Turn out just probably a slight misalignment of the lock, so I saw a small piece sticking out from the lock, when I pull it, it unlocks the door and I was able to open the door and when I plug it back again, it works!