On my system this problem/crash occurs on 0.63 experimental as well as the current stress test #31. The log files were created while trying the stress test.
When I start normally over Steam:
When I start DayZ_x64.exe as administrator I am able to get ingame. When joining a server, DayZ crashes without an error message. After that the game restarts and I experience the same as when starting it over Steam.
Log files:
DxDiag: