After updating the latest patch and launching DayZ .53 from steam, blank screen. On checking background, I found an application error window reading "The instruction at 0x007981b8 referenced memory at 0x00000000. The memory could not be read. etc". This is the first time this has occurred. Reproducable every attempt at launching.
Will check integrity of files and reinstall if necessary.

Fresh spawn, approaching Novo, crash (played 1 minute).
relogged, entered truck park above Novo, crashed (played 1 minute).
relogged (and rebooted), entered Novo, climbed Hotel stairs, crashed (played 10 minutes).

Already posted under Issue# 15591

equip akm, go prone (mouse5), zoom (hold mouse2), fire (k), unzoom (click mouse2), standup and throw gun (no control).

Version 0.50 stable and experimental both allow binding of mouse 1 (left) to any controls. Mouse 2 (right) is still restricted to zoom regardless of configuration.