For anyone who still has problems, What i did today was (if using DayZ Commander) 1.Uninstall DayZ Commander. 2.Go to Local Disk C: 3.Program Files or Program Files x86. 4.Steam. 5.Steam apps. 6.Common. 7.Arma 2 Operation Arrowhead. 8.Delete all the @Dayz files weather its @dayz Epoch just anything that has @Dayz at the beginning. 9.Open Steam and uninstall Arma 2 Operation Arrowhead. 10.At the same time uninstall the Arma 2 Operation Arrowhead Beta. 11. Install Arma 2 Operation Arrowhead. 12.When that is fully installed, install the beta version. 13.Open them both up after installing them. 14.Reinstall DayZ Commander and click install next to Arma 2 in the install/update tab. This should now help please reply if this works i really hope it works for you happy zombie killing! :D
