When i started Area 51 on SP mission, after few mintuers got finally destroy their cars and exact moment i press F6 and save the game and poof the game crash, i cant load this game it just crash.. whataaaaa do?

You aren't supposed to destroy them, main quest outside is destroy turret and run through corridor. Inside you supposed to destroy few cars (or your friend help) and hit to elevator, kill commander, pick up weapon on switch, run all the way down through tunnels to center of alien craft, kill the queen and shoot weird bulbs with alien gun to activate teleport.

Hmm well that kinda strange, still i cant load that Area 51 the loading keep crashing to desktop... or wait, nwm i can try again on new game so i can pick the mission so i can try that again