Recently my son was editing some of his videos for youtube. He came to me with a problem. Vegas was crashing. It would lock up and then force close. I suspected It could be the Video card, or maybe a corrupt system file. Turns out it was just a corrupt index from his imported Media.
Figuring this out I ended up swapping the video card, and even reinstalling the entire operating system and Vegas Pro. But when he opened up his project file, it still would still crash after a few seconds. Vegas would only crash if we loaded his most recent project. If it was a new project, no problem. This lead me to beleive that there was something wrong with the media files he imported. I suspected that the indexes that Vegas creates when you import new media might have become corrupt. So I went into the project folder, and deleted the indexes. Then the next time we loaded the project Vegas automatically made new indexes for the media, which took a few minutes to complete. After that no more issues. Hopefully this tip helps other with the same issue.