My Development:UE5.7,vs2026,SDK:steamworks_sdk_164.
Trying out the Multiplayer TPS game C tutorial, using Steam Online Subsystem for multiplayer. After packaging, I used two Steam accounts: one as host to create a lobby, and the other to join. My join can find the corresponding lobby but just can’t get in.
this my DefaultEngine.ini
[OnlineSubsystem]
DefaultPlatformService=Steam
[OnlineSubsystemSteam]
bEnabled=true
SteamDevAppId=480
bInitServerOnClient=true
bUseSteamNetworking=true
[/Script/Engine.GameEngine]
!NetDriverDefinitions=ClearArray
+NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="OnlineSubsystemSteam.SteamNetDriver",DriverClassNameFallback="OnlineSubsystemUtils.IpNetDriver")
[/Script/OnlineSubsystemSteam.SteamNetDriver]
NetConnectionClassName="OnlineSubsystemSteam.SteamNetConnection"
this a Plugin of multiplayersession ：MultiplayerSessions.Build.cs
PublicDependencyModuleNames.AddRange(
new string[]
{
"Core",
// ... add other public dependencies that you statically link with here ...
"OnlineSubsystem",
"OnlineSubsystemUtils",
"OnlineSubsystemSteam"
,"UMG" , "Slate",
"SlateCore",
}
);
this a my main MyTPSGame.build.cs
// Copyright Epic Games, Inc. All Rights Reserved.
using System.IO;
using UnrealBuildTool;
public class MyTPSGame : ModuleRules
{
public MyTPSGame(ReadOnlyTargetRules Target) : base(Target)
{
PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;
PublicDependencyModuleNames.AddRange(new string[] {
"OnlineSubsystem",
"OnlineSubsystemSteam",
"SteamSockets",
"OnlineSubsystemUtils",
"Core",
"CoreUObject",
"Engine",
"InputCore",
"EnhancedInput",
"AIModule",
"StateTreeModule",
"GameplayStateTreeModule",
"UMG",
"Slate"
});
PrivateDependencyModuleNames.AddRange(new string[] { });
PublicIncludePaths.AddRange(new string[] {
"MyTPSGame",
"MyTPSGame/Variant_Platforming",
"MyTPSGame/Variant_Platforming/Animation",
"MyTPSGame/Variant_Combat",
"MyTPSGame/Variant_Combat/AI",
"MyTPSGame/Variant_Combat/Animation",
"MyTPSGame/Variant_Combat/Gameplay",
"MyTPSGame/Variant_Combat/Interfaces",
"MyTPSGame/Variant_Combat/UI",
"MyTPSGame/Variant_SideScrolling",
"MyTPSGame/Variant_SideScrolling/AI",
"MyTPSGame/Variant_SideScrolling/Gameplay",
"MyTPSGame/Variant_SideScrolling/Interfaces",
"MyTPSGame/Variant_SideScrolling/UI"
});
// Uncomment if you are using Slate UI
// PrivateDependencyModuleNames.AddRange(new string[] { "Slate", "SlateCore" });
// Uncomment if you are using online features
// PrivateDependencyModuleNames.Add("OnlineSubsystem");
// To include OnlineSubsystemSteam, add it to the plugins section in your uproject file with the Enabled attribute set to true
string SteamworksDir = "C:/steamworks_sdk_164/sdk";
string DllPath = Path.Combine(SteamworksDir, "redistributable_bin/win64/steam_api64.dll");
RuntimeDependencies.Add("$(BinaryOutputDir)/steam_api64.dll", DllPath);
}
}
log:
[2026.06.14-15.46.11:873][507]LogNet: Verbose: Registering network metrics listener /Script/Engine.NetworkMetricsPerfCounters for metric AddedConnections
[2026.06.14-15.46.11:873][507]LogNet: Verbose: Registering network metrics listener /Script/Engine.NetworkMetricsCSV_Replication for metric RawPing
[2026.06.14-15.46.11:873][507]LogSockets: Warning: SteamSockets: Cannot get information on an invalid socket handle, returning null
[2026.06.14-15.46.11:873][507]LogNet: Warning: Could not create socket for bind address 76561198413382025, got error SteamSockets: setsockopt SO_BROADCAST failed (0)
[2026.06.14-15.46.11:873][507]LogSockets: Warning: SteamSockets: Cannot get information on an invalid socket handle, returning null
[2026.06.14-15.46.11:873][507]LogNet: Warning: Could not create socket for bind address ::, got error SteamSockets: setsockopt SO_BROADCAST failed (0)
[2026.06.14-15.46.11:873][507]LogNet: Warning: Encountered an error while creating sockets for the bind addresses.
[2026.06.14-15.46.11:873][507]LogNet: Error: InitBindSockets failed:
[2026.06.14-15.46.11:873][507]LogNet: Warning: Failed to init net driver ConnectURL: steam.76561198693598889/Game/ThirdPerson/Lvl_ThirdPerson:
[2026.06.14-15.46.11:874][507]LogNet: Warning: error initializing the network stack
[2026.06.14-15.46.11:874][507]LogNet: DestroyNamedNetDriver: Name:PendingNetDriver Def:GameNetDriver IpNetDriver_2147482397
[2026.06.14-15.46.11:874][507]LogGlobalStatus: Warning: UEngine::BroadcastTravelFailure Travel failed, type: ETravelFailure::PendingNetGameCreateFailure, reason: “Error initializing network layer.”
[2026.06.14-15.46.11:874][507]LogNet: Warning: Travel Failure: [PendingNetGameCreateFailure]: Error initializing network layer.
[2026.06.14-15.46.11:874][507]LogNet: TravelFailure: PendingNetGameCreateFailure, Reason for Failure: ‘Error initializing network layer.’
[2026.06.14-15.46.11:874][507]LogGlobalStatus: Warning: UEngine::BroadcastTravelFailure Travel failed, type: ETravelFailure::ClientTravelFailure, reason: “”
[2026.06.14-15.46.11:874][507]LogNet: Warning: Travel Failure: [ClientTravelFailure]:
[2026.06.14-15.46.11:874][507]LogNet: TravelFailure: ClientTravelFailure, Reason for Failure: ‘’
[2026.06.14-15.46.11:874][507]LogGlobalStatus: UEngine::Browse Started Browse: “/Game/ThirdPerson/Lvl_ThirdPerson?closed”
[2026.06.14-15.46.11:874][507]LogNet: Browse: /Game/ThirdPerson/Lvl_ThirdPerson?closed
[2026.06.14-15.46.11:874][507]LogNet: Connection failed; returning to Entry
[2026.06.14-15.46.11:874][507]LogLoad: LoadMap: /Game/ThirdPerson/Lvl_ThirdPerson?closed
[2026.06.14-15.46.11:874][507]LogWorld: BeginTearingDown for /Game/ThirdPerson/Lvl_ThirdPerson
[2026.06.14-15.46.11:874][507]LogViewport: Display: Viewport MouseLockMode Changed, DoNotLock → LockOnCapture
[2026.06.14-15.46.11:874][507]LogViewport: Display: Viewport MouseCaptureMode Changed, NoCapture → CapturePermanently
[2026.06.14-15.46.11:875][507]LogViewport: Display: Player bShowMouseCursor Changed, True → False
[2026.06.14-15.46.11:876][507]LogWorld: UWorld::CleanupWorld for Lvl_ThirdPerson, bSessionEnded=true, bCleanupResources=true
[2026.06.14-15.46.11:877][507]LogSlate: InvalidateAllWidgets triggered. All widgets were invalidated
[2026.06.14-15.46.11:877][507]LogWorldPartition: UWorldPartition::Uninitialize : World = /Game/ThirdPerson/Lvl_ThirdPerson.Lvl_ThirdPerson
[2026.06.14-15.46.11:930][507]LogAudio: Display: Audio Device unregistered from world ‘None’.
[2026.06.14-15.46.11:935][507]LogRenderer: Forcing update for all mesh draw commands: SkyLight real-time capture change
[2026.06.14-15.46.11:944][507]LogUObjectHash: Compacting FUObjectHashTables data took 0.55ms
[2026.06.14-15.46.11:947][507]LogStreaming: Display: FlushAsyncLoading(64): 1 QueuedPackages, 0 AsyncPackages