Is the dishwasher level? 

Make sure the dishwasher is level. The dishwasher must be supported by the leveling legs and rear wheels and must be flat on the floor. Some models will have four leveling legs. The dishwasher must also be square in the cabinet. If the tub opening is not square, the door will not seal properly. This is the responsibility of the customer or installer.   Learn how to use your phone to level household appliances. 

Are there items between the door seal and the tub of the dishwasher? 

• Check that no items, such as silverware, are stuck between the door seal on the dishwasher door and the dishwasher's tub. This will cause the door not to shut or seal properly. 
• Check both racks for items that may be stuck and protruding. Remove any item that is protruding outside the rack.
• Check for large food particles around the door seal. Large items could cause the door not to shut or seal properly.