Receiving NAT punchthrough attempt from target 684547167205435679 failed..

hello I have a game with multiplayer but now when a clients joins I get this error: "Receiving NAT punchthrough attempt from target 684547167205435679 failed"

When I launch a server is use this: var useNat = !Network.HavePublicAddress(); -Network.InitializeServer(GameMaxPlayers-1, 8935, useNat);

-MasterServer.RegisterHost(GameMode,GameName,"");

When connecting I use this: -Network.Connect(element);