Well, everytime i wanna play crysis 2, i want to replay a mission. But everytime i do that, just when the loading is done, the game crashes. Same happens when i want to start a new campaign. I can only load a game, but thats boring cos the game is already halfway done then. Need some help with this please.

Alse, ive recently downloaded the Dx11 and highresolution from the site, but when i go to options, i cant enable either of them. Anyone knows whats wrong? I have the 1.9 patch and did the 2 downloads for Dx11 and high res afterwards.

Hmm, DX11 and HRTP made some interesting things to some players, while enabled. Make sure you have the latest drivers installed for your setup. On the other hand, does your video card support DX11? If not, you won't be able to turn it on, the button will still remain inactive. As for the HRTP, I don't know why it won't give you an option to turn it on. One thing that always works for me is reinstalling the whole game.
But if you have some time, wait for a person who's more experienced or have a sollution to your problem, personally, I did not have any during using them in-game.