So I have the Combined Operations from retail (bought Arma 2 and OA seperatly and joined them). Everything is fine, but lately i have been needing to use the steam chat function in game. I tried adding the Arma2oa.exe file through " Add non-steam games" function in steam but when ever i try running it i get a error creating Direct3D 9 graphical engine error I tried adding the cmd file here. So if anyone has any suggestion please do tell !