I submitted a ticket and this worked for me: A recent update of ARMA2 Operation Arrowhead my have been applied incorrectly. If you are using Steam, your game was automatically updated as part of the Stream update process. It is possible that the update process may have corrupted one or more files. To repair this, do the following. * Close down steam, and start it as administrator. To do so, find Steam in your start menu, right-click on the shortcut and select Run as Administrator. * Go to your game library and locate ARMA2. Right-click on the game and select "Properties". Click on the "Local Files" tab. Click on "Verify integrity of game cache". This process may take a bit of time as Steam verifies your game files. * Once this is done, do the same for ARMA2 Operation Arrowhead. * Launch ARMA2 and then close/exit the game. This is to ensure that Steam finishes any installation or reconfiguration. * Launch ARMA2 Operation Arrowhead and close it. * If you use Six Updater, launch Six Updater and optionally update the mod to the latest version. If you're using other means of launching DayZ, update or launch the mod accordingly.