http://forums.dayzgame.com/index.php?/topic/220946-the-instruction-at-0x00d1b2e2-referenced-memory-at-0x00000000-the-memory-could-not-be-read/
^^ forum thread where people have similar issues and have posted screenshot of the error.
HAVE TRIED: Verifying integrity, downloading drivers, restarting steam/PC, launching as administrator, launching in compatibility mode
(have not tried a fresh install as is not feasible with my internet, others who have report this to not be a fix : see thread above)