**Fixed for me**
Make sure you don't have a over clocked GPU!!
I was getting Mantle errors and DX errors at random times from 3 sec crash to an hour before crashing. I tried new drivers, changing settings, etc... hours of reading forums... Was getting very frustrated.
I have an AMD R9 280X Gigabyte Windforce 3gb
After seeing it mentioned in a few posts scattered about (and on troubleshoot page) that the game doesn't like over clocked GPUs (mine is Factory over clocked) I finally decided to give it a shot so I used the program GURU II to "underclock" my GPU back from 1100mhz to 1000mhz and absolutely no crashes have happened since in ten hours of playing. I know this wont help all but some of you might want to make sure you are not having issues due to this same problem. (Reposting to help)
