I have played ArmA3 for ages and have 2987 hours on it. And have been using the launcher ever since it came out. And never had any problem at all in fact i have played arma2 and arma for ever and i have never had ANY problems with any of it. This is my first problem and i haven't changed anything. I exually was playing i stopped playing to watch a few video's i started my game and this happend.
I have tested a few fixes like:
Re-installing the game
Restart the computer
Launching both steam and arma as Administrators and in compatibility mode
Verified game cache
Restarted steam
im out of options right now