The same thing happened on my x but it wouldn't open from the outside either!

Its either the carrier assembly or the actuator (more likely the latter).

I bought a new actuator and then had to pull off the interior panel with the door closed! It will be a lot easier as your door opens.

So take off the door panel and spray the actuator and lock assembly with loads of WD40 or lube and keep working the interior and exterior handles with the door open.

With a bit of luck it might free itself, It worked for me and I took the new actuator back to BM for a refund.