Hammer Constantly Crashing?

[The Mad Muffin]

I haven't used Hammer in a long time but now that I've come back to it I'm finding it 100% unusable on my PC. Whenever I switch between the various tabs in object properties, Hammer just suddenly crashed out on me. I can't figure out what's wrong with it, I tried reinstalling it and verifying the game cache.

I'm in the L4D2 Authoring Tools version of it, I haven't tried any other version. Has anyone had this problem? What other info do you need? Because right now I can't get anything done at all when I have to stop and save every single time I select an entity for fear of crash.