GTA IV MP: Can't play online with specific freind

[HazMatt]

Me and a few other friends attempted to play GTA IV online (PC). However, there is a very frustrating issue.

It seems that me and one other friend cannot connect to each other. I cannot join his server, and he cannot join mine. In fact, I cannot join any server that he is on (even public ones) and he cannot join any that I am on. This issue only occurs with us two. I can connect to every one else fine, and so can he (just as long as he and I are not connecting to the same server).

 

 

The error messages we receive when attempting to join his server is:

 

The first is "Unable to connect to the game session". This sends me back to the server browser and allows me to continue searching.

 

The second one is "Disconnected from game session." This kicks me back to single player and I have to use the phone to get back to multiplayer.

 

It's the same two errors when he tries to join my servers.

 

 

We all have legitimate copies of the game and working Games for Windows Live accounts.

Our NAT's are open, not strict (according to GFWL settings)

My friend has a Steam digital copy, while mine was bought retail and installed on a disk. I don't think this would be the problem, however, because I am able to join another friends server without problems, and he has a Steam copy as well.

I have Windows 7, while my friend has Windows 8.

 

I have heard many people discussing port forwarding when it comes to online issues. However, not many people say that it works.

 

This post had good feedback, but I have not come to a fix yet.

http://forums.steampowered.com/forums/show...d.php?t=2044235

 

 

If anybody has any help or advice to offer, it would be greatly appreciated!

Edited January 18, 2013 by HazMatt

[HazMatt]

Please, anyone who has any sort of networking knowledge could be the one to fix the problem.

If this problem happens to you too, tell me. Two brains are better than one!