What does 3 flashing lights on indesit IDF125 dishwasher mean?

What does 3 flashing lights (wash,dry and end lights continually flashing) on indesit IDF125 dishwasher mean? and how do I fix it?
It seems a bit random as to when it will work and when it won't. It has just stopped after the wash before the dry this time, but stopped after the prewash last time. We have checked the water inlet and filters.