99% chance you have a bad AV and said AV is blocking the game from loading properly. Otherwise it could be a variety of things. Maybe go and delete your key and GFX configs from the game's players2 folder, so the game uses stock settings. Just make note of your sensitivity beforehand.
If it's your AV just make an exception for the game's entire folder. If I were you I'd just uninstall the AV. Haven't used an AV personally for the past 9 years now, since the only thing you truly need is adblock + a pop up blocker for your browser. AVs are more headache than they're worth, but that's up for you to decide. If you need it, you need it.

me trying to fix this issue has given me an aneurysm, i just want to play zombies in spaceland. :(