QuickTime player crash

I am trying to digitize my old vhs tapes and ive had good luck until I tried to add a clip to the end of another video and then tried to replace the existing file with the same name. When I hit replace my computer completely quit for a few minutes and when I turned it on my quicktime player would not open, the file never got saved fully. And now I cant even start over bc it will not open at all. Ive reported it to apple but it makes me sad I cant continue my project