Inlet/Drain Warning Light Flashing?

Miele G654 SC plus dishwasher starts, you hear the motor for a few seconds and then stops with the inlet/drain light on. Water from previous wash had drained ok. I’ve checked the filter combination, drain pump impellor and water inlet filter and hose – all clear. No water in base of machine and the water leak protection microswitch clicks on/off when you press it. I pulled the dishwasher out so that the drain hose was not kinked, still didn’t work. I tried pressing combination of start/stop and on/off buttons for about 4 minutes to see if the machine reset itself but to no avail. Has anyone got any idea what the problem is and how to fix it ??