on mine that has happened twice. There is a rod with a L on the end from the lock that goes into a hole on the door latch. If it comes loose the door will not unlock with the key or fob. Yes you can remove the screws on the inside plate where the handle is and get at the mechanism. There must have been some kind of retainer but it is lost so I used duck tape.
I also met someone a while back who just could not open the door but the latch and lock seem to be working fine. I just pulled real hard and it opened. After applying lube to the stub on the door frame where the latch attaches when the door closes, it worked fine.