Hey can someone PLEASE help us play this game? What's going wrong with how we have set it up?

Hi guys, both my friend and I have installed the coop mod client-0.9.3.7.zip and also the ScriptHookVDotNet.zip files. F9 doesn't work but we can see each other in the Rockstar friends menu and we can even see each other and send invites to each other on the mods game server but we can't see or recieve each other's game invites. Can someone help please?

Thanks Simon