You fixed the problem yet? I just got my ArmA 3 day before yesterday and I got the same issue. My game crashes in exact 15 min after launch. No matter it's single, multiplay or just stay in main menu, after 15 min, crash. I tried pretty much everything but formatting. Here's the list that I tried :
-Reinstall
-Reinstall in different HDD.
-Verify game cache
-Restart computer after install
-Set every .exe to admin
-Increased virtual memory
-malloc=system (and tried other options too.)
-Set parameter option
-Graphic card driver update
-Windows update
-Defragment
-Memory check
-Turned off anti-virus program
-Delete all dll files
-Pray to gods.
All this in vanilla game. No mods, no DLCs. I tried send my crash dump to the dev via support form but everytime I tried to send, it says 'error' and I should contact via support form if this keeps up. The form that just gave me that error.
Answers in wiki are useless. And it seems only some people with win 10 64bit suffer this problem. I don't know what I should do next. I just wanted enjoy the game. Is it too difficult to ask?
My computer :
Win 10 64
Geforce 970
16GB Ram
i7 something with 8-cores
God help me plz