As per my report #0022645 ever since the 3/11/2015 patch I wasn't able to launch DayZ. I verified the game cache through Steam, re-installed c++ and finally uninstalled and then re-installed DayZ. Nothing worked. I then closed out my peripheral programs one by one to see if any of them were causing a conflict, I.E., Teamspeak, Razer Synapse, Seagate dashboard, etc. Finally I determined it was Razer Synapse. Someone on Reddit had the same problem and this solution worked for them, too.