Stealth_Trooper

I strive for realism personally and I've beaten the game before with PK's. However, I want to play around with other mods. Unfortunately, when I start a new campaign, if I have any of the downloaded mods loaded it'll crash the game and give me some stupid error. I'm not sure why it's not working. I put all the mods in the proper folder. [silent Storm not S3] I made sure to download the no-pk mod for S2. Is it because I have the American version of the game and not the UK? Anyhow, any help would be greatly appreciated. Thanks