What is your model number? If this is the style with a handle that you just pull to open (no button or latch to push on to unlock latch) then you'll want to check dishwasher installation in the cabinet. Sometimes the dishwasher can get pushed back causing it to twist or sit incorrectly making the door pop open.
If the install looks good, check the door hinges. If the door opens past 90°, the hinges are bent and it won't close.