I've had this problem when trying to import a media file to work with, I record and edit some bits of gameplay and upload them to YouTube. On certain recordings for some reason I get the messages almost instant saying "movie maker transcoder has stopped working" and does not allow me to edit anything. I have read many solutions to this problem such as uninstalling and reinstalling, restarting my machine and I even tried to record my recording to see if that works. Nothing came to a solid solution.