So I've been playing up NV as I wait to download some mods here (it's going to be like Black Friday), and much to my anger, the game isn't working. Although my mouse is confirmed to be working still, it doesn't pan around to make my character face different directions, and although that is another issue I need help with, there's another one - once I'm in game, the screen just totally locks up, and it's kind of like the all-too-common black screen - except this one is olive. It doesn't say my game is "not responding", since I can effortlessly tab back in and out, and I can still pull up the pause menu. I've been nerdraging all night, and the only thing that annoys me more than the wait of possible promotion is the thought of being promoted and then not being able to play my game, which I'm really enjoying.

Will someone help me?

I'm quite busy at the moment, but somehow (as always) found time to get on.

Try these:
1. Do you have any mods installed? If so then uninstall them one at a time and load up your saved game and narrow down the culprit
2. Start up a new game
3. I know this one's a pain but sometimes needed; reinstall your game, as in first wipe it's face off your drive completely (meaning main folder, with Data and the launcher, and your Documents/My Games/FNV)
4. Run LOOT. Powerful and comprehensive tool, very useful for determining crashes and conflicts in your load order

That's all I can think of right now. I am in quite a jiff so I sorta rushed this. Sincerely hope I could help you, if not our other fantastic members might be able to find the root of your problem.

Good luck Mac!