So when I add a video file to Movie Maker everything is fine, but as soon as I use the "split" tool on the video, everything after the split becomes blank, both on the preview and on the thumbnails.

I have absolutely no idea what the problem is. I set the program's priority to "high", and my computer has 8GB of RAM, it also has a really good processor.

This same thing happened when I was trying to edit long videos on my laptop (which is very bad and crappy), so I don't think it's a problem with hardware.

This only happens when I do it with 20+ minute clips.

Someone please help. I've been sitting here for literally 2 hours just trying to figure out how to fix it.