This has nothing to do with Dayz. Its a steam problem.

Try rename the file steamservice.exe located in steam folder. There is two of them on my computer. This solves the problem on Windows 10.

Exactly the same thing happend to me yesterday in a stair on the factory nere the town location (023 011). Was standing with a firend. Opened up the inventory and was pressing ESC to change video settings. Boom you are dead. Ho shoot no Zombi. Me firend was able to recover all my stugg since he was new spawned.