see if you can verify the game's local files (steam library>right click arma 3>properties>local files tab>verify integrity of game crash, I think that's where you find it) because it may be that you have missing or damaged game files. If that doesn't fix it or there aren't any missing files, you might try moving all your mods to a separate folder and try playing the game without any of them installed, just incase it's a bad mod that is causing the problem.

hi.
Game files are all fine. Crash happens with and without mods. I've already tryed it with a reinstall of the game and with an nother operating system (windows 7-64 and windows 8.1 64)
Doesn't the game save some kind of "crash report" or something like that? If yes, please tell me where because I don't know how to find it.

Hi,
yes, you can find crashreports here: C:\Users\<Name>\AppData\Local\Arma 3\
Could you please upload these files? (.rpt, .mdmp, .bidmp)¨
Thank you.

Ok, I hope these informations are helpful. :(

Would be awesome, if you would be able to give me an information if the files could help you and if you are working on the problem.

p.s.
Sorry for my bad English :(

We will see, thank you for your files. Our programmers will look on your crashdump files.

Hey,
I have the same issue. It drives me crazy, especially during wastelands multiplayer (but it can also crash in main menu) :/

I attached crashdump.* (with dumps for 3 same-looking recent crashes I remember), and DxDiag_mark (as dxdiag output). I hope it will help you solve the issue :)

As I checked, the possible quick-fix is to go to ARMA3 directory and in properties change compatibility mode to Windows XP Service Pack 3 and check 'Run as Administrator' :)