We have a Smeg dishwasher - Retro-style - STFABUPB-1

It has worked wonderfully for 6 months. Recently it will stop mid cycle and start flashing an "E" on the digital display.

We tried with no success:

1- resetting the program
2- taking the drains/pieces out and cleaning them
3- checking for lodged food, glass
4- flipped the circuit breaker to reset the dishwasher

There is a small amount of dirty water in the bottom of the drain/filter. It is starting to smell. I cannot get it to drain completely or finish a cycle.

Suggestions? Advise?

Thanks in advance!
JD