Friend can't join me but i can join him.
I can join him just fine but if he tries joining me absolutely nothing happens. even if he does the connect [IP]:[port] I port forwarded and enabled upnp and everything else seems like it would work. but it doesn't and for whatever reason it refuses to let him join.
Try to add a firewall exception for the specific port you forwarded.
Also make sure he is trying to connect using the corrent ip and port that you actually forwarded.