G-Mod Aftermath Game mode not working

So i’ve done what all the threads have told me, i installed the svn files in (steam/steam apps/steam user/ garrysmod/garrysmod/) and each time i hop onto the server i’m just stuck looking at a windmill.
I’ve uninstalled and reinstalled the svn files twice, i uninstalled garrys mod then reinstalled garrys mod and nothing it still doesn’t work, so is there a specific way to start playing the server or have i done something wrong?

If anyone knows a way i can fix it and play, that would be great.
Thanks

Btw im playing on a mac