Hosting an online session

[Riley Preston]

Hello, I've recently downloaded some add-ons because we want to have a V8 supercars league. The problem is when one of us tries to host, the other cannot join (you just click join and nothing happens).

I haven't touched any of the ports or anything so what exactly do we have to do to get this to work? We tried just using a race 07 track and cars but it still didn't work so the add ons are definitely not the problem.

thanks


EDIT: He has opened all the ports and tried with and without a dedicated server, still not working