Diplomate dishwasher will not click shut. ?

Hi, i don't know if this will be the same solution as others, but my dishwasher door does not click shut - it was working fine, then went to use it and will not shut - there is nothing blocking it (seems like some kind of safety feature). The salt try seems to be filled with water - don't know if that is anything to do with it. It is a built in Diplomat dishwasher. Any help would be really greatfull. Thanks