Hey
I just want to point in my case DCS will crash if there is no allowance to connect DCS.exe with internet.
I use ESET Smart Security 7.
I made test, ran DCS in Multiplayer mode and DCS was "thinking" forever after clicking "connect" button in Login panel.
After patience you click on it and common Windows window shows, DCS is not responding and what you wanna do. I close it because DCS is frozen already :)
With enabled allowance (disabled firewall) it runs normally, but the multiplayer code is overall a bit crap so far (GUI freezes from time to time), in game too.