Enable UPnP
- Open router admin (often 192.168.1.1 or 192.168.0.1)
- Find UPnP or NAT-PMP — enable
- Save and reboot router
- Restart PC
Gaming routers
Enable “Open NAT” or “Gaming mode” if available.
Corporate / dorm networks
UPnP is often blocked — you may be unable to host; join someone else’s lobby instead.