CRASH ON STARTUP? (FIX!)
First, you need to go to the local black ops files
You can do this by going to your library right click the game.
Click properties, go the local files, and lastly click "Browse Local Files"


If you can't find this, here's the directory:
C:\Program Files (x86)\Steam\steamapps\common\Call of Duty Black Ops III Beta

Once there, simply delete the file named "video" relaunch the game and you will be able to play.

*If this didn't work, I am sorry, but otherwise I hoped this helped the people who couldn't even launch the game.*