I have both Arma 2 and Arma 2: OA. When I start up OA everything is fine with no error messages. I get to the main menu and all is well except for the option of single player being gray. I can click on every other option from the main menu but single player. I do not know what to do or how to fix it. I have already tried uninstalling and installing again. Also I run it through Steam. Please help!