Unexpected GSPolicyResponse callback ue5 dedicated steam server

Hello,

i am trying to make a dedicated steam server for my Game.
I am using to Advanced Session and Advanced Steam Session plugin.
I am using UE5.6 from source Build
For now I am using AppID=480

Everytime I start the dedicated Server I got the Errors shown in the server log.
Does someone have the same Problem?

I already tried with SteamSockets and without, no difference…
I need help.

Thanks -

OnlineSessionAsyncServerSteam.cpp

#ifndef UE_PROJECT_STEAMPRODUCTNAME
#define UE_PROJECT_STEAMPRODUCTNAME "spacewar"
#endif //UE_PROJECT_STEAMPRODUCTNAME

#ifndef UE_PROJECT_STEAMGAMEDIR
#define UE_PROJECT_STEAMGAMEDIR "spacewar"
#endif // UE_PROJECT_STEAMGAMEDIR

#ifndef UE_PROJECT_STEAMGAMEDESC
#define UE_PROJECT_STEAMGAMEDESC "Spacewar"
#endif // UE_PROJECT_STEAMGAMEDESC

Server.Target.cs

using UnrealBuildTool;
using System.Collections.Generic;

public class Extraction_ShooterServerTarget : TargetRules
{
    public Extraction_ShooterServerTarget(TargetInfo Target) : base(Target)
    {
        Type = TargetType.Server;
        DefaultBuildSettings = BuildSettingsVersion.V5;
        IncludeOrderVersion = EngineIncludeOrderVersion.Unreal5_6;
        ExtraModuleNames.Add("Extraction_Shooter");

        GlobalDefinitions.Add("UE_PROJECT_STEAMSHIPPINGID=480");
        GlobalDefinitions.Add("UE_PROJECT_STEAMPRODUCTNAME=\"spacewar\"");
        GlobalDefinitions.Add("UE_PROJECT_STEAMGAMEDIR=\"spacewar\"");
        GlobalDefinitions.Add("UE_PROJECT_STEAMGAMEDESC=\"Spacewar\"");
        GlobalDefinitions.Add("UE_SERVER_USE_PRESENCE=0");
    }
}

DefaultEngine.ini

[/Script/Engine.GameEngine]
!NetDriverDefinitions=ClearArray
+NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="/Script/SteamSockets.SteamSocketsNetDriver",DriverClassNameFallback="/Script/SteamSockets.SteamNetSocketsNetDriver")

[OnlineSubsystem]
DefaultPlatformService=Steam

[OnlineSubsystemSteam]
bEnabled=True
SteamDevAppId=480
SteamAppId=480
bUseSteamNetworking=false

[/Script/SteamSockets.SteamSocketsNetDriver]
NetConnectionClassName="/Script/SteamSockets.SteamSocketsNetConnection"

[PacketHandlerComponents]
+Components=OnlineSubsystemSteam.SteamAuthComponentModuleInterface

Server Output Log:

LogSteamShared: Display: Loading Steam SDK 1.57
LogSteamShared: Steam SDK Loaded!
Setting breakpad minidump AppID = 480
LogOnline: STEAM: [AppId: 480] Game Server API initialized 1
LogOnline: STEAM: AUTH: Steam Auth Enabled
LogOnline: OSS: Created online subsystem instance for: STEAM
LogOnline: OSS: TryLoadSubsystemAndSetDefault: Loaded subsystem for type [STEAM]
LogConfig: Applying CVar settings from Section [/Script/CompositeCore.CompositeCorePluginSettings] File [Engine]
...
[2025.10.07-17.22.59:408][  0]LogWorldPartition: Display: WorldPartition initialize started...
[2025.10.07-17.22.59:408][  0]LogWorldPartition: UWorldPartition::Initialize : World = /Game/level/MapMaster/MapMaster.MapMaster, World Type = Game, IsMainWorldPartition = 1, Location = V(0), Rotation = R(0), IsEditor = 0, IsGame = 0, IsPIEWorldTravel = 0, IsCooking = 0
[2025.10.07-17.22.59:408][  0]LogWorldPartition: UWorldPartition::Initialize Context : World NetMode = Dedicated Server, IsServer = 1, IsDedicatedServer = 1, IsServerStreamingEnabled = 0, IsServerStreamingOutEnabled = 0, IsUsingMakingVisibleTransaction = 0, IsUsingMakingInvisibleTransaction = 0
[2025.10.07-17.22.59:408][  0]LogWorldPartition: Display: WorldPartition initialize took 322 us
[2025.10.07-17.22.59:412][  0]LogLoad: Game class is 'GM_GameMode_C'
[2025.10.07-17.22.59:412][  0]LogCsvProfiler: Display: Metadata set : iris="0"
[2025.10.07-17.22.59:412][  0]LogNet: ReplicationDriverClass is null! Not using ReplicationDriver.
[2025.10.07-17.22.59:412][  0]LogNetCore: DDoS detection status: detection enabled: 0 analytics enabled: 0
[2025.10.07-17.22.59:412][  0]LogNet: InitBase GameNetDriver (NetDriverDefinition GameNetDriver) using replication model Generic
[2025.10.07-17.22.59:413][  0]PacketHandlerLog: Loaded PacketHandler component: Engine.EngineHandlerComponentFactory (StatelessConnectHandlerComponent)
[2025.10.07-17.22.59:413][  0]LogNet: Name:GameNetDriver Def:GameNetDriver SteamSocketsNetDriver_2147482478 started listening on 7777
[2025.10.07-17.22.59:413][  0]LogWorld: Bringing World /Game/level/MapMaster/MapMaster.MapMaster up for play (max tick rate 30) at 2025.10.07-19.22.59
[2025.10.07-17.22.59:413][  0]LogWorld: Bringing up level for play took: 0.000270
[2025.10.07-17.22.59:416][  0]LogLoad: Took 0.021529 seconds to LoadMap(/Game/level/MapMaster/MapMaster)
[2025.10.07-17.22.59:416][  0]LogGlobalStatus: UEngine::LoadMap Load map complete /Game/level/MapMaster/MapMaster
[2025.10.07-17.22.59:419][  0]LogInit: Display: Engine is initialized. Leaving FEngineLoop::Init()
[2025.10.07-17.22.59:419][  0]LogLoad: (Engine Initialization) Total time: 2.30 seconds
[2025.10.07-17.22.59:453][  0]LogLiveCoding: Display: Successfully initialized, removing startup thread
[2025.10.07-17.22.59:453][  0]LogTrace: Display: Control listening on port 34350
[2025.10.07-17.22.59:519][  3]LogSteamSocketsAPI: Warning: SteamSockets API: Warning SDR network config fetch attempt #1 failed.  HTTP 504.  .  Trying again.
[2025.10.07-17.22.59:553][  4]LogSteamSocketsAPI: Verbose: SteamSockets API: Log Got SDR network config.  Loaded revision 1757966882 OK
[2025.10.07-17.22.59:553][  4]LogSteamSocketsAPI: Verbose: SteamSockets API: Log Performing ping measurement
[2025.10.07-17.22.59:554][  4]LogSteamSocketsAPI: Verbose: SteamSockets API: Log SDR RelayNetworkStatus:  avail=Attempting  config=OK  anyrelay=Attempting   (Performing ping measurement)
[2025.10.07-17.23.03:176][114]LogSteamSocketsAPI: Verbose: SteamSockets API: Log Ping measurement completed in 3.5s.  Relays: 23 valid, 3 great, 10 good+, 15 ok+, 7 ignored
[2025.10.07-17.23.03:176][114]LogSteamSocketsAPI: Verbose: SteamSockets API: Log Ping location: ams=15+1,fra=15+1,ams4=24+2/16+1,lhr=25+2/20+1,par=23+2/24+1,vie=29+2/26+1,sto2=35+3/35+1,sto=40+4/35+1,waw=35+3/36+1,iad=110+11/101+1,gru=211+21/215+2,sgp=265+26/220+18
[2025.10.07-17.23.03:177][114]LogSteamSocketsAPI: Verbose: SteamSockets API: Log SDR RelayNetworkStatus:  avail=OK  config=OK  anyrelay=OK   (OK.  Relays: 23 valid, 3 great, 10 good+, 15 ok+, 7 ignored)
[2025.10.07-17.23.05:381][181]LogSteamSocketsAPI: Verbose: SteamSockets API: Log Gameserver logged on to Steam, assigned identity steamid:90275216748947457
[2025.10.07-17.23.05:382][181]LogSteamSocketsAPI: Verbose: SteamSockets API: Log AuthStatus (steamid:90275216748947457):  Attempting  (Requesting cert)
[2025.10.07-17.23.05:382][181]LogSteamSocketsAPI: Verbose: SteamSockets API: Log Set SteamNetworkingSockets P2P_STUN_ServerList to '155.133.248.38:3478' as per SteamNetworkingSocketsSerialized
[2025.10.07-17.23.05:648][189]LogSteamSocketsAPI: Verbose: SteamSockets API: Log AuthStatus (steamid:90275216748947457):  OK  (OK)
[2025.10.07-17.23.05:648][189]LogSteamSocketsAPI: Verbose: SteamSockets API: Log Certificate expires in 48h00m at 1760030585 (current time 1759857784), will renew in 46h00m

[2025.10.07-17.23.05:714][190]LogOnline: Warning: STEAM: Unexpected GSPolicyResponse callback
[2025.10.07-17.23.19:454][608]LogOnline: Warning: OSS: Async task 'FOnlineAsyncTaskSteamCreateServer bWasSuccessful: 0' failed in 15.001879 seconds
[2025.10.07-17.23.19:455][608]LogBlueprintUserMessages: [GI_Mutiplayer_Sessions_C_2147482567] Server Start Failed

I also encountered the same problem. I also tried using SteamSocket, but it didn’t improve

Having the exact same issue on 5.6.1

Any news or is this a downgrade angle?

I have the exact same error (5.6.1). Tried to troubleshoot it for the past week but i just cant get it to work either. I tried all the different configurations for the DefaultEngine.ini, WindowsEngine.ini and WindowsServerEngine.ini. Because the Unexpected GSPolicyResponse callback comes from steam its hard to debug in UE itself. The problem only seems to be with a dedicated server setup tho. Creating a listen session works (there are other problems later on with joining the session, but creation works). By now i think this must be a Bug in the SteamOSS in 5.6.1. I just hope that maybe 5.7 fixes it.