ok! This is one of the biggest problems with the mod as far as I've read the forum. I also had this, but I managed to resolve it. However there are a lot of suggestions, so it might be quite random. (Look and you will find a solution is what I'm saying) What I had to do was to copy all my files from "C/Program files/steam/SteamApps/common/arma 2/AddOns" TO "C/Program files/steam/SteamApps/common/arma 2 operation arrowhead/common" As I understand you have to "Copy and replace"! If this doesn't resolve it, there are quite a few other "ways" to do it that you may try. Good luck! was a pain in the ass, but you will figure it out :)