Windows Movie Maker corrputed file

Hi!

I was making a movie in Windows Movie Maker when the program blocked while I was splitting one of the imported videos. I closed the program, clicked "save changes" and when I tried to reopen my project I got the message that Movie Maker could not open the file because the file might be corrupted. I looked this message up on the internet and saw it was a recurring problem. I have tried all the solutions I found (make a copy in Notepad etc.), but I can't get it fixed. Also, Microsoft does not provide support for this anymore. Is there anyone who could fix this problem for me? I would be eternally grateful!