Edit: I'm using Sony Vegas Movie Studio 9.0
My cousin and I have been trying to make a movie this summer, and we filmed some footage, using a Sony Webbie (cheap HD camcorder) which uses mp4 files. I get the mp4 files into the computer using a memory stick PRO duo, and it gets into the computer okay. But after importing many (maybe about 70) little clips of video (mp4) into Vegas and editing them, I can't import anymore files into it. I have more mp4 files that are already on the computer that I need to import into Vegas. Every time I try to import another video into Vegas, another video clip fails (it'll say "An error occurred opening the media file...What do you want to do? - Specify a replacement file - Ignore error and leave media offline - Ignore this and all subsequent media errors").
I've tried re-installing Vegas and getting rid of unnecessary programs on my computer to save space (in an attempt to get more videos into Vegas). All has failed. Does anyone have an idea of what the problem might be?