I have no problem playing CO-OP on my PC.
This problem is user related.
You will need to disable your Anti-virus programs, disable your Windows Firewall, disable your UpNp and SSDP in services and in router. Also check in router your NAT type, it must be OPEN.
Regards
I already have all that set up. Not that I am happy about that. No other game I've ever come across requires AV to be off and NAT fully open. Idiotic.
Anyway, as I said, I have already set up the forwarding, turned off UpNp and SSDP, and all that. It still won't join Co-op games.
Your move.
