Tho this was an old issue, I am having this issue with BitDefender now, today.
I actually had issues with Kaspersky with this game too - tho I used to just totally shut down Kaspersky and I could then play the game, and turn it back on. BitDefender has protections that make it so you can not totally shut it down without uninstalling it. Something still runs, even tho it's *supposed* to be just like the starter system when you put it in game mode it still is conflicting with the game...
As mentioned turning on "Game Mode" doesn't help me at all. I still can't enter missions with BitDefender up (without the Abnormal Action problem kicking me out within a few seconds that is). I turn on Game Mode, I even manually tell the program to not run the AntiVirus and most every other component and it still boots me and has this problem just having the base BitDefender running without it actually doing anything.
Uninstalling definitely does work - but should I have to uninstall? BitDefender was expensive and is supposed to be one of the very best money can buy. I can't afford to just throw the money away or have one of the very best protections that we paid for ignored just for a single game.
So Game Mode is working for other people? I wonder why it's not working for me. It's the newest version of BitDefender Total Security 2013 anyway specifically. This post was old, is Game Mode still working for other people with the newest BitDefender today?
I wonder if I sent the problem in to BitDefender if they would see if they could fix it or not or if it's just beyond that.
I like the game and I want to play (and even spend money on it) but I will pick my paid for virus protection over the game in the end if things can't be worked out.