a este le pasó lo mismo y esa fué la solucion

[B]I had this problem after moving some videos to an external hard drive. After reading the above post I changed how the folder is viewed from 'thumbnails' to 'list'. Simply open the folder, right click an empty part of the folder and select 'view', 'list'. Now I can open the folder without the error message. It must be to do with the way the 'thumbnail' view uses the codecs to create a preview image of the videos. I'm very happy this is now resolved![/B]