We used to run WMC using BD ISO files through PowerDVD for our HTPC. Now, with all of your help, we've been converting to MP4 video through Apple TV and couldn't be happier. However, I ran into an interesting situation. I have tried to convert 4 Blu-Ray movies. They were: Lion King Transformers 3 Avatar Iron Man Transformers 3 and Avatar worked without issue. However, the Lion King and Iron Man- When I chose open video file, and brows to the folder containing the MKV of that movie, Handbrake (Windows) stops responding. Likewise, if I use Windows Explorer and browse to this folder...again Windows Explorer stops responding, and crashes. The only thing I can possibly do is delete the movie's MKV via command line. all MKVs are created from the ISO using MakeMKV. Any idea on to what is going on?