I've owned ARMA3 for over a year and I've never had this problem before. I bought the game for my brother and he had this issue on his laptop. I've played this game on both a laptop and currently on a new computer build that I completed a couple months ago. The computer currently uses Windows 10, but this issue only showed up just now.
The only thing that comes to mind that could possibly (but not likely) cause this is that I downloaded DayZ just last night, and now this issue has appeared.
https://onedrive.live.com/redir?resid=12A4D67888711078!114&authkey=!ALNm6Q-pK6Dtqh8&ithint=file%2czip