[Unable to Reach Game Server, make sure your ports are open.]

Called my ISP today to double check the ports being open, and confirmed with them that they are. They restarted the service and made sure the port was open again, but still seem to have this error

[Unable to Reach Game Server, make sure your ports are open.]

This is the message i receive when i try to host a server. Yes my ports are opened up, me and my friend who are trying to connect, have the same software version, but neither one of us can seem to host a server to have us connect to eachother. Any help would be awesome!