Garry's Mod Freezes at Startup

I don’t appreciate this. I don’t. I am getting sick and tired, and I need to do something with Gmod. I can’t use it because it freezes on start up. And when I try to validate the game, it says that “1 file faild to validated and will be reaquired.” What file?! Which file is it talking about?! I DON’T KNOW!

Just help me, please! I am already pissed off as I am, and I am having a hard time trying to get it working again. Please help me!