I reinstalled DirectX from the Arma 3 Folder and installed the newest Nvidia Drivers, my Sounddrivers are up to date same goes for my Mainboard drivers and Bios.
Included in the Arma3.rar are all files from the Arma3 Folder and my DxDiag.txt file.
EDIT1:
This error only occurs on Multiplayer with any server,map and scenario it does not crash at all in Singleplayer