It could be a number of things, you should have it checked immediately.

Crucial website will have that information.

You need to do a master reset. Go on the internet, type in your model, find reset procedure.

Disconnect battery terminals, touch the ends together for one minute, reconnect battery. Hope this helps.

if the button won't push in to open the microwave door, one of the little ears that holds the button in place has broke off and is keeping the button fron being depress. Find someone who works on appliances remove the cabinet cover, remove the door release latch, pop out the button and remove the broke ear, pop the button back in, replace the latch, reinstall the cabinet cover and your good to go.