gmod crashing when loading main menu

i need help with gmod because it worked fine thursday but not yesterday it crashed when it tries to load the mainmenu up all it says hl2.exe has stopped working thing is i played hl2 yesterday with no problem so can anyone help me?

Try verifying game cache, also have you changed anything since then?

Try to re-install gmod. Only downside of that is addons will be deleted, and have to re-download (Note: You don’t have to subscribe to all the addons again they will automaticly download)