It turns out it was a lot of my files in C:\Program Files (x86)\Steam\steamapps\common\DayZ\Addons

I had to manually remove the Addons folder, uninstall DayZ, then re-install. When I would just uninstall from steam and clear all local files it would keep the old .pbos?

installed 0.56 experimental and upon opening the game it crashes with a /bin/chenarus.pbo corrupt.

Getting something similar.

APPLICATION ERROR
The instruction at 0x004a15d2 referenced memory at 0xb4a90000. The memory could not be read.

and also

APPLICATION ERROR
The instruction at 0x678cb99c referenced memory at 0x01a5e01e. The memory could not be read.

Side note, I have erased all launch parameters.