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...
(http://image.prntscr.com/image/408879dc25f84b168aaa17b34bbc2315.png)
... 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.
(http://image.prntscr.com/image/ff0f433aedeb408a931b50c530ad8271.png)
Try that and see if your game launches.