Recently, my friend was able to track down his long lost AC2 letsplay series from 2 years back, and there are about 15 episodes. Each one comes in two files, the original .vf file as well as the backup file - vf.bak. He tried opening all of them with Sony Vegas, sadly whenever he tried to render them into MP4 or any video format he was told the file was either corrupted or of an unknown format. Since I have low Sony Vegas experience, or in general editing, I can't professionaly adress all the information about the file types. However, we tried several methods we found from online forums. We renamed the files, tried to put them in a RAR archive, moved into seperate folders, and so on. Another method we found is looking for a restored video or an auto save somewhere in app data, but we couldn't use that method since my friend doesn't use the same version of Vegas that he did while creating those projects. Clearly the files are damaged and I need to restore them in one way or another, but I couldn't find a proper free tool that could restore Vegas projects. Any help is appreciated, and I'm willing to share anything I can find out that might help in tracking down the issue. His OS right now is windows 10.