Same problem here, I used to be able to play DayZ but now it comes up with this error message. It says ingame on the server list I am running 1.6.2, but the server requires 1.62.<heaps of random numbers> I've tried completely reinstalling Arma 2, DayZ, and OA to no avail. Could someone find the solution to this please? I was going to do a group expedition with my friends but now I can't even join a single server. <SOLVED Woo, I found the solution! :D The thing that's probably wrong is, that you have the beta installed (as Commander tells you) but commander doesn't actually run the beta, since you have a wrong .exe in OA folder. Go to the ...\Steam\steamapps\common\arma 2 operation arrowhead\Expansion\beta -folder, and copy the OA.exe file from there to the location: ..\Steam\steamapps\common\arma 2 operation arrowhead\ Commander updates that file automatically when you update using it (if the option is enabled of course). Now you need to do it manually, since you didn't have this option enabled when you updated.
