Can't join friends games. Can't send him arrangement team invites. It keeps failing. How to fix this?

Tried the sticky didn't work. No firewall is on either. I have the port and it works for 1 computer but not for this one.

Why?

u cant join maybe coz they are not able to host? und u cannot sent invitation for arranged team coz u cant host. its about port 6112, u must unlock it with ur router/firewall.

sometimes 2 users just cant connect to eachothers games cause their blocked by 1 or both of ur providers ...

tried this few times before

www.portforwarding.com ..

your friends can invite others?