That happened to my last coach. If it is a door that opens up and is not covered with that black plastic it is easy to fix.
First, open another door and look at the black gizmo and see how it is attached to the lock. IT is a white or grey plastic piece on a metal arm. That is your goal.
If the solenoid is locked shut and the plastic is broken inside it will not turn with the key at all so you have to remove it from the lock.
Now you have to raise the coach up as high as you can and get a 1/4 inch narrow flat blade and long 15″ – 16″ screwdriver and a pair of needle-nose pliers.
I pulled the black weather-stripping out and then used a flashlight and peered up till I could see the metal arm.
I then pushed the plastic piece off the arm and then the key will work. It took me about an hour the first time and 10 minutes the next time it happened.
I have not done it on a door that is covered in the plastic on the rear but I am sure it will work the same way just harder to see in that is all.
Look at a door that is similar and open before you do it. It was done this way on a 99 and 2000 coaches but I have not had to do it in my 2001 yet. John Sichenze 2/6/2008
On our 1999 U320 I had to push a coat hanger (never hung a coat on one, but sure got into lots of locked things with them <grin>) with a hook on the end so I could grab one of the cables and pull it to release the handle.
Look at a working door and see if you can do the same thing. I spent a while on my back poking away (managed to avoid tearing the seal too) but finally got it.
The second time I got locked out, it went much faster – the Bride crawled through from the other side! Dave & Barb Jenkins 2/6/2008