We have a Miele Inspira G2120/G2140 that's had light use (once a week) for 6 years. Getting the rinse, dry, end lights error about 10 to 15 minutes into cycle (have tried multiple programs). Dishwasher fills and drains, and water seems to circulate, but then cycle just stops with the error. I took the dishwasher apart to get directly to the motor and circulation pump, and the impeller (?) seems to turn freely. Put the unit back together, and getting the same error. Any help is appreciated.