Ok normally when you get this fault water has leaked into the base of the dishwasher so its activated the flood switch so then it brings the pump on running all the time.
What you need to do is pull the dishwasher out and tip it backwards and this will allow the water in the base to drain out so you will need a towel for this part.
Once the water has drained out stand it upright and retry the dishwasher and fingers crossed that should cure the fault and get it up and running again.
Let me know how it goes.
Light has gone off and I am now trying a wash.
Fingers crossed this has cured it. But if it does it again then im afraid theres a leak in there which you will need to find and fix to cure it.