Clean light flashes 4 times, water standing in tub

Hi everyone,

I think this dishwasher is about two years old. This morning, the clean light and also the front indicator were blinking four times. Closing or opening the door, it beeps 15 times. The unit cannot be reset. The other buttons beep when pushed but the dishwasher is not operational.

There is some water standing in the tub.

I checked the cylindrical filter, and it is clear.

It had been repaired once before, but I can't recall why.

Any ideas would be most appreciated!