I had the exact same issue a few weeks ago. It was booked into the dealer (they do a software update, if that doesn't work they try to free up the actuator which is prone to getting stuck, and if all else fails they replace the part).
Weirdly the problem resolved itself the day before. Not sure if it was anything I did (the only thing I did that was out of the ordinary that day was remove/replace the usb stick). You could try restarting the mtc (pressing both buttons for 10-20 seconds I believe), but I'm afraid the only other solution is a trip to the dealer I think.