I've downloaded the 506th mod and extracted the files. However, it won't allow me to launch ARMA 3. It says Include file userconfig\cyp_pushtohear_a3\cyp_pushtohear_a3_config.hpp not found.
The
userconfig folder in the .zip file...
... needs to end up in your root Arma 3 directory. (Typically, this directory is something like
C:\Program Files (x86)\Steam\steamapps\common\Arma 3 .)
There is likely already a userconfig folder there; if so, merge the userconfig included in the 506th modpack.
Try that and see if your game launches.