Think it through logically. Water is inside the dishwasher washing the dishes. Water should not be on the tray underneath so water should not be leaking out of any screw holes down there. You will probably find the leak is either from the main wash pump or the plastic water delivery tube up the back wall. You will need to remove the side panels, dry out the tray and then run it with the panels off and watch for where the water comes from then decide what to do about it.
Lincoln Appliance NZ, March 2013