Jibbinator

So recently I managed to get my OverPoch working. I joined a server, played for 20 minutes, then the server restarted. I tried rejoining it and it said: FILES "C:\Program Files (x86)\Steam\steamapps\common\Arma 2 Operation Arrowhead\@DayZ\addons\dayz.pbo", "C:\Program Files (x86)\Steam\steamapps\common\Arma 2 Operation Arrowhead\@DayZ\addons\dayz_anim.pbo", "C:\Program Files (x86)\Steam\steamapps\common\Arma 2 Operation Arrowhead\@DayZ\addons\dayz_code.pbo", "C:\Program Files (x86)\Steam\steamapps\common\Arma 2 Operation Arrowhead\@DayZ\addons\dayz_communityassets.pbo", "C:\Program Files (x86)\Steam\steamapps\common\Arma 2 Operation Arrowhead\@DayZ\addons\dayz_equip.pbo", "C:\Program Files (x86)\Steam\steamapps\common\Arma 2 Operation Arrowhead\@DayZ\addons\dayz_sfx.pbo", ... are not signed by a key accepted by this server. To play on the server, remove listed files or install additional accepted keys. After that, I joined a different DayZ Overpoch server and joined just fine, played for about 2 hours and then the server restarted. I tried rejoining it after the restart and the same error popped up.. It is a fault in the server? Or something to do with my system?

I'm sure this problem has something to do with ArmA 2: Combined Operations, a lot of people who don't use OverWatch or Epoch have this problem too, I just can't seem to find the solution anywhere. This was my last solution, to write a thread.