If your problem is from missing maps or textures, i suggest downloading the files you need from garrysmod.org and placing them in your gmod addons folder. That should fix any missing map errors, also if you can not connect still, try going to options and enabling download while loading that way you download the required files for DarkRP while joining the server.

If your problem is from missing maps or textures, i suggest downloading the files you need from garrysmod.org and placing them in your gmod addons folder. That should fix any missing map errors, also if you can not connect still, try going to options and enabling download while loading that way you download the required files for DarkRP while joining the server.