Enforcer249 0 Posted May 7, 2020 When I launch ARMA 2 and ARMA 2 OA, It's shut down itself. I have no idea what is wrong with this game. The only I could find clue, It's Steam error massage; 'Invalid Session Key'. I did nothing wrong. Maybe It went something wrong when game update, but It usually work fine before. I know this game is very old and no one play this game anymore but I hope someone see this post. Share this post Link to post Share on other sites
