Only reason why the game would crash when showing a movie would be because it cannot show/draw whatever the movie requests your game client to show or if they're in such a demanding spot with so many users your game/computer cannot handle.
If you can run around in most maps and play the game without crashing the latter shouldn't be the case, which makes it sound rather like it's something with the moviecammovements file being tinkered with as it's used when making "movies" in the game, but I cannot confirm that it crashes the game if it's not in the game as I've never checked or tried it. Everything else that shows in the movie is literary stuff your game already loads and draws up when you go in game, such as materials for characters, maps you go to, your characters, animations and actions.
