OK, please try this:
You will have to unplug the appliance and remove the bottom front flap.
Then keep some beach towels and shallow container under the filter.
Now, rotate the drain pump filter anti clockwise to open, clean it completely and make sure it is not clogged.
Also with your fingers check if impellor rotates, then reconnect everything and plug it back.
Press and hold the START button and plug it back.
Let go off the button after around 10 seconds.
Then turn it on and turn it back off and turn it back on.
If you still see this error then press and hold the start button again and then turn the dial one click anti clockwise then back to off.
Repeat this step for around 4-5 times.
Then try any program and please let me know how it goes.