I would like to update something about this error message that some users might get start searching for a match with someone in your party.
Me and some testers have some reasons that might be the cause. The following reasons are what we think it might cause. But they could be wrong. We are still investigating on this problem.
1. Missing some specific DLC
2. NAT type to moderate or Strict
3. Router Ports, DMZ or Firewall not configured properly for Ghosts Multiplayer.
Reason #3 might be the most plausible. I tested with someone who had the error showing and after some configuration (router I guess), we managed to make it worked. Like mentioned above we are investigating to find the source of the problem. Thank you for your patience. =) For now, it is the best I can offer you as a Lobby Editor. I would like to apologize to people who are having issues with the tool.
-:Ports To Configure:-
-:How to activate DMZ:-
TCP: 1116-1150, 28910
UDP: 1116-1150, 5165, 27900-27901
(This tutorial is for Lynksys Router Users)
Hopefully, this will help a lot of users =)
1. Enter Router Configuration by entering 192.168.1.1 (Default) in an Internet Navigator
2. Enter admin login to gain access to the router's configuration page. Default should be No Username and admin as password
3. Click on "Application & Gaming" and on DMZ sub-category
4. Click Enable
5. Source IP should be "Any IP Address"
6. Destination IP should be you private address. Mine is 192.168.1.109. To find you private IP, open Command Prompt (CMD), type : ipconfig and look under IPV4 Address. This is you private IP.
7. Once entered, Hit "Save Settings"
8. Reboot Game.