On my Sony Bravia TV, when I'm trying to play videos from a USB, the movie will play for a bit (one minute, usually) and then the screen will suddenly say "Playback Not Available". It's a MPEG4 file, which IS playing at first, so it can't be a problem with the file type.
Also, this morning, I managed to get an entire tv episode to play on my TV from the USB, and it was also an MPEG4. But now this isn't playing..? So what can the issue be? And how can I fix it so I can watch the entire movie?