After the 1.38 update this week, my Arma 3 would just die on launch with no error message at all.
I tracked it down to a memory registry setting done by the "GimmieMoarFrames" procedure.
Here's the relevant link:
http://forums.bistudio.com/showthread.php?177454direct link to the off file:
https://github.com/fred41/GimmeMoarFrames/blob/master/GimmeMoarFrames/GMF_Off.regMy registry setting was different than that file (windows 7 64bit) and was found here:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\arma3.exe
Some current issues, and possible resolutions:
http://steamcommunity.com/app/107410/discussions/0/620703493320198228/It was also recommended to delete all the memory allocators in steamapps/common/Arma3/Dll and just use the system memory allocator for windows 7 and up. I haven't fully tested this yet, so do at your own peril.
While searching, I also came across a new network setting to help with lower bandwith. Just add "-bandwidthAlg=2" to your launcher line to use the new network code. It seems to work quite well after the last 3 ops.