Advanced Sessions Plugin – Unable to Join Sessions (UE5)

[X_Hangman_X (HangmanTheDev)]

Hello everyone!

I know this question has been asked many times, and I’ve read everything I could find on the topic — but I still can’t get it to work!
I’ve spent over 40 hours this past week trying to solve it, and I’m stuck.

Does anyone have an idea what I am doing wrong, or is the plugin broken?

My theory
Looking at the logs, it seems like I’m trying to join the MainMenu map, while the host (running a listen server) has already switched maps using ?listen.
These log lines make me think something isn’t working correctly with the Steam subsystem. The logs mention the IpNetDriver, this should be SteamNetDriver I think?

LogSockets: Warning: GetAddressInfo failed to resolve host with error SE_HOST_NOT_FOUND [11001]

LogNet: UNetConnection::Close: [UNetConnection] RemoteAddr: , Name: IpConnection_2147482359, Driver: Name:PendingNetDriver Def:GameNetDriver IpNetDriver_2147482422, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID, Channels: 3, Time: 2025.06.27-18.55.50

LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = PendingConnectionFailure, ErrorString = Your connection to the host has been lost., Driver = Name:PendingNetDriver Def:GameNetDriver IpNetDriver_2147482422

About the Project

• Build editor from source 5.6.0
• Using Advanced Sessions Plugin 5.6 from here.
• C++ and Blueprint, only doing Blueprint code so far. (With one empty C++ class)

What I did so far

• Build the Engine from source
• Added Plugins to Project
• Added new C++ class
• Created AdvancedFreindsGameInstance and implemented OnSessionInvitaAccepted
• Updated .uproject, .ini and Build.cs
• Cleaned and Re-Compiled Project successfully
• Added steam_appid.txt to Build and Project directory
• Packaged Project for WinDev

What works

• Steam interface
• Creating a session via CreateAdvancedSession
• Finding sessions via FindSessionsAdvanced

What does not work

• Joining the session via FindSessionsAdvanced → JoinSession
• Joining Session via Steam-Invite
  The client will get an error and the host will see a successful join.

Testing on two different machines with two different Steam accounts but the same build from one machine.

Debug output Client joining via ServerList

LogSteamShared: Display: Loading Steam SDK 1.57
LogSteamShared: Steam SDK Loaded!
LogOnline: Verbose: STEAM: Steam: Starting SteamWorks. Client [1] Server [1]
Setting breakpad minidump AppID = ****
SteamInternal_SetMinidumpSteamID:  Caching Steam ID:  *** [API loaded no]
LogOnline: STEAM: Steam User is subscribed 1
LogOnline: STEAM: [AppId: ***] Client API initialized 1
LogOnline: STEAM: [AppId: ***] Game Server API initialized 1
LogOnline: Verbose: STEAM: Created thread (ID:7092).
LogOnline: OSS: Created online subsystem instance for: STEAM
LogOnline: OSS: TryLoadSubsystemAndSetDefault: Loaded subsystem for type [STEAM]

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Verbose: STEAM: Starting search for Internet games...
LogOnline: Verbose: STEAM: FOnlineAsyncEventSteamLobbyUpdate LobbyId: Lobby[0x1860000D8028E35]
LogOnline: Verbose: OSS: Async task 'FOnlineAsyncTaskSteamFindLobbiesForFindSessions bWasSuccessful: 1 NumResults: 1' succeeded in 0.309148 seconds
LogOnlineSession: STEAM: Found 1 lobbies, finalizing the search
LogOnlineSession: STEAM: Search result 0: LobbyId=Lobby[0x1860000D8028E35], LobbyId.IsValid()=true, CSteamID(LobbyId).IsLobby()=true
LogScript: Script Msg: Found a session. Ping is 9999

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 Verbose: STEAM: FOnlineAsyncEventSteamLobbyEnter LobbyId: Lobby[0x1860000D8028E35] Result: '1' k_EChatRoomEnterResponseSuccess (Success)
LogOnline: Verbose: STEAM: FOnlineAsyncEventSteamLobbyUpdate LobbyId: Lobby[0x1860000D8028E35]
LogOnline: Verbose: OSS: Async task 'FOnlineAsyncTaskSteamJoinLobby bWasSuccessful: 1 Session: GameSession LobbyId: Lobby[0x1860000D8028E35] Result: '1' k_EChatRoomEnterResponseSuccess (Success)' succeeded in 0.248246 seconds
LogOnlineVoice: OSS: StartLocalProcessing(0) returned 0xFFFFFFFF
LogOnlineVoice: OSS: Starting networked voice for user: 0
LogOnlineVoice: OSS: RegisterLocalTalker(0) returned 0x00000000
LogOnlineVoice: OSS: Invalid user specified in RegisterLocalTalker(1)
LogOnlineVoice: OSS: Invalid user specified in RegisterLocalTalker(2)
LogOnlineVoice: OSS: Invalid user specified in RegisterLocalTalker(3)
LogOnlineSession: STEAM: Using P2P Data for Connection Serialization
LogOnlineSession: OSS: Join session: traveling to steam.76561198094895081:7777
LogBlueprintUserMessages: [DungeonGameInstance_C_2147482570] Joined Session
LogGlobalStatus: UEngine::Browse Started Browse: "steam.76561198094895081/Game/TheDungeonProject/Levels/Level_MainMenu"
LogNet: Browse: steam.76561198094895081/Game/TheDungeonProject/Levels/Level_MainMenu

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Created socket for bind address: 0.0.0.0:0
LogNet: IpConnection_2147482359 setting maximum channels to: 32767
PacketHandlerLog: Loaded PacketHandler component: Engine.EngineHandlerComponentFactory (StatelessConnectHandlerComponent)
LogHandshake: Stateless Handshake: NetDriverDefinition 'GameNetDriver' CachedClientID: 4
LogNet: Game client on port 7777, rate 100000
LogNetVersion: TheDungeonProject 1.0.0.0, NetCL: 0, EngineNetworkVersion: 42, GameNetworkVersion: 0 (Checksum: 1220682179)
LogSockets: Warning: GetAddressInfo failed to resolve host with error SE_HOST_NOT_FOUND [11001]
LogNet: UNetConnection::Close: [UNetConnection] RemoteAddr: , Name: IpConnection_2147482359, Driver: Name:PendingNetDriver Def:GameNetDriver IpNetDriver_2147482422, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID, Channels: 3, Time: 2025.06.27-18.55.50
LogNet: UNetConnection::SendCloseReason:
LogNet:  - Result=AddressResolutionFailed, ErrorContext="AddressResolutionFailed"
LogNet: UChannel::Close: Sending CloseBunch. ChIndex == 0. Name: [UChannel] ChIndex: 0, Closing: 0 [UNetConnection] RemoteAddr: , Name: IpConnection_2147482359, Driver: Name:PendingNetDriver Def:GameNetDriver IpNetDriver_2147482422, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID
LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = PendingConnectionFailure, ErrorString = Your connection to the host has been lost., Driver = Name:PendingNetDriver Def:GameNetDriver IpNetDriver_2147482422
LogNet: Warning: Network Failure: PendingNetDriver[PendingConnectionFailure]: Your connection to the host has been lost.
LogNet: NetworkFailure: PendingConnectionFailure, Error: 'Your connection to the host has been lost.'
LogNet: DestroyNamedNetDriver: Name:PendingNetDriver Def:GameNetDriver IpNetDriver_2147482422
LogRHI: Display: Encountered a new graphics PSO: 1911018763
LogGlobalStatus: UEngine::Browse Started Browse: "/Game/TheDungeonProject/Levels/Level_MainMenu?closed"
LogNet: Browse: /Game/TheDungeonProject/Levels/Level_MainMenu?closed
LogNet: Connection failed; returning to Entry
LogLoad: LoadMap: /Game/TheDungeonProject/Levels/Level_MainMenu?closed
LogWorld: BeginTearingDown for /Game/TheDungeonProject/Levels/Level_MainMenu
LogWorld: UWorld::CleanupWorld for Level_MainMenu, bSessionEnded=true, bCleanupResources=true

Accepting and invite

Creating a session

Joining a session via ServerList

Game.uproject

{
	"FileVersion": 3,
	"EngineAssociation": "{1C66A00B-408B-CA94-EF65-18953AAB5918}",
	"Category": "",
	"Description": "",
	"Modules": [
		{
			"Name": "Game",
			"Type": "Runtime",
			"LoadingPhase": "Default"
		}
	],
	"Plugins": [
		{
			"Name": "ModelingToolsEditorMode",
			"Enabled": true,
			"TargetAllowList": [
				"Editor"
			]
		},
		{ "Name": "AdvancedSessions",      "Enabled": true },
		{ "Name": "AdvancedSteamSessions", "Enabled": true },
		{ "Name": "OnlineSubsystemSteam",  "Enabled": true },
		{ "Name": "SteamShared",           "Enabled": true },
		{ "Name": "OnlineSubsystem",       "Enabled": true } 
	],
	"TargetPlatforms": [
		"Windows"
	]
}

DefaultEngine.ini

[/Script/Engine.GameEngine]
!NetDriverDefinitions=ClearArray
+NetDriverDefinitions=(DefName="GameNetDriver", DriverClassName="OnlineSubsystemSteam.SteamNetDriver", DriverClassNameFallback="OnlineSubsystemUtils.IpNetDriver")

[OnlineSubsystem]
DefaultPlatformService=Steam
bHasVoiceEnabled=true

[OnlineSubsystemSteam]
bEnabled=true
SteamDevAppId=*** (My own from steam)
SteamAppId=*** (My own from steam)

; If using Sessions
bInitServerOnClient=true

[/Script/OnlineSubsystemSteam.SteamNetDriver]
NetConnectionClassName="OnlineSubsystemSteam.SteamNetConnection"

Game.Build.cs

using UnrealBuildTool;

public class Game: ModuleRules
{
	public Game(ReadOnlyTargetRules Target) : base(Target)
	{
		PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;
	
		PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "AdvancedSessions", "AdvancedSteamSessions" });

		PrivateDependencyModuleNames.AddRange(new string[] { "OnlineSubsystem", "OnlineSubsystemSteam" });
	}
}

[Raveelll]

Have the same issue. Tried everything with the same result.
Also created a new clean project only with Advanced Sessions Plugin on UE 5.6 to make sure that there is nothing wrong with my existing project and joining session process is exactly the same.

[b1gdaddybear]

I’m using 5.6 with my game and it’s working - including fixing the issue of ping(ms)which is now working. You need to put the Steam_Appid.txt in the packaged directory of /name of game/Binaries/Win64/…

I also have these settings in my DefaultEngine.ini:

[OnlineSubsystem]
DefaultPlatformService=Steam
bHasVoiceEnabled=true
VoiceNotificationDelta=0.2
MaxLocalTalkers=1
MaxRemoteTalkers=16
PollingIntervalInMs=20
bUseBuildIdOverride=false
BuildIdOverride=0
!AdditionalModulesToLoad=Clear
+AdditionalModulesToLoad=HTTP
+AdditionalModulesToLoad=XMPP

[OnlineSubsystemSteam]
bEnabled=true
SteamDevAppId=2052340
bInitServerOnClient=true
bUsesPresence=true
bUseLobbiesIfAvailable=true
bUseSteamNetworking=true
bAllowP2PPacketRelay=true

[/Script/OnlineSubsystemSteam.SteamNetDriver]
NetConnectionClassName=“OnlineSubsystemSteam.SteamNetConnection”

[STRiFE.x (STRiFE)]

Is there anyone who can run the Online Subsystem Steam properly in UE 5.6?

Hi, I’m trying to migrate my project from UE 5.5.4 to UE 5.6. Everything has been going well so far, except for the Steam integration. The scenario is as follows; A hosting player runs the packaged game on a PC with Steam Account - A and creates a lobby session and successfully travels to lobby map via server travel. World->ServerTravel(PathToLobby); Another player (client) runs the same packaged game on another PC with Steam Account - B and tries to join host player A. PlayerController…