Now it works....Jehaaa! So i have deinstalled Arma 2 and OA. Then i installed first Arma 2, the patches and started the game. Then i installed OA with the new betapatch and started the game. After that i put the @DayZ folder into the OA Folder and start it with _runA2CO_beta.cmd file. But first you have to edit the file like this: http://dayzmod.com/forum/showthread.php?tid=10729&highlight=_runA2CO_beta And now i see lots of zombies...hell yeah :D