F&P 913T Dishwasher - only starts when front of dishwasher is tilted upward?

My F&P Model 913T dishwasher refused to start. Found that lifting up front of washer slightly starts the dishwasher going but when front of dishwasher is lowered the machine stops. Have tried lowering the back using the adjustable feet but that does not help. Have recently replaced the main front door seal to stop water leakage. The fault with having to raise the front started about the same time as seal was replaced.
Any one had a similar problem and did they fix it?