# Steam Online Subsystem not working in packaged build (UE5.6) **URL:** \ **Category:** Platform & Builds\ **Tags:** onlinesubsystem, Steam, unreal-engine, question\ **Created:** [August 31, 2025, 8:14pm UTC](https://forums.unrealengine.com/t/steam-online-subsystem-not-working-in-packaged-build-ue5-6/2652620 "2025-08-31T20:14:21Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![KOHNSSER](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@KOHNSSER](https://forums.unrealengine.com/u/KOHNSSER)\ **Post date:** [August 31, 2025, 8:14pm UTC](https://forums.unrealengine.com/t/steam-online-subsystem-not-working-in-packaged-build-ue5-6/2652620/1 "2025-08-31T20:14:21Z")
I’m testing multiplayer with the Steam Online Subsystem in Unreal Engine 5.6. Everything works fine inside the editor, but when I run the packaged build, it doesn’t connect to Steam. In the logs I get these warnings: LogSteamShared: Warning: SteamAPI failed to initialize, conditions not met. LogOnline: Warning: STEAM: Steamworks: SteamUtils() failed! LogOnline: STEAM: [AppId: 0] Client API initialized 0 LogOnline: OSS: Unable to create OnlineSubsystem instance STEAM **What I’ve tried:** - Created `steam_appid.txt` with `480` inside. - Placed `steam_api64.dll` next to the EXE. - Running the build with the Steam client open. **Issue:** When I try to host a game, it seems to enter the map for a split second and then immediately kicks me back to the main menu. ---
**Author:** ![Abbalm](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Abbalm](https://forums.unrealengine.com/u/Abbalm)\ **Post date:** [September 5, 2025, 7:45am UTC](https://forums.unrealengine.com/t/steam-online-subsystem-not-working-in-packaged-build-ue5-6/2652620/2 "2025-09-05T07:45:11Z")
I’m hitting the same issue and still haven’t found a solution. Here’s what I’ve also verified: - **OnlineSubsystemSteam** plugin is enabled in the Editor (Plugins). - It’s set to `"Enabled": true` in the **.uproject** file. - The modules are referenced in **.Build.cs** (`OnlineSubsystem`, `OnlineSubsystemUtils`, and `OnlineSubsystemSteam` as a dynamically loaded module). - Both players are set to the **same Steam download region**. - **DefaultEngine.ini** is configured like this: ```auto [/Script/Engine.GameEngine] !NetDriverDefinitions=Clear +NetDriverDefinitions=(DefName="GameNetDriver", DriverClassName="/Script/OnlineSubsystemSteam.SteamNetDriver", DriverClassNameFallback="/Script/OnlineSubsystemUtils.IpNetDriver") [OnlineSubsystem] DefaultPlatformService=Steam bUseBuildIdOverride=true BuildIdOverride=1 [OnlineSubsystemSteam] bEnabled=true SteamDevAppId=480 SteamAppId=480 bInitServerOnClient=true bAllowP2PPacketRelay=true P2PConnectionTimeout=90 [/Script/OnlineSubsystemSteam.SteamNetDriver] NetConnectionClassName="/Script/OnlineSubsystemSteam.SteamNetConnection" [/Script/OnlineSubsystemUtils.IpNetDriver] NetServerMaxTickRate=120 ``` Despite all of this, the client often can’t find the session at all (Find Sessions returns 0 results). I’ve been stuck on this for a while and it’s getting frustrating, especially with how little clear documentation there is about getting OnlineSubsystemSteam up and running. Has anyone found additional steps or common pitfalls we might be missing (particularly when using AppID 480/Spacewar)? Any pointers or diagnostics to enable would be greatly appreciated. ---
**Author:** ![brs-sebascova](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/brs-sebascova/32/1052483_2.png) [@brs-sebascova](https://forums.unrealengine.com/u/brs-sebascova)\ **Post date:** [September 5, 2025, 6:45pm UTC](https://forums.unrealengine.com/t/steam-online-subsystem-not-working-in-packaged-build-ue5-6/2652620/3 "2025-09-05T18:45:20Z")
Hello there! This conflict has showed around the community from time to time, usually with the same patterns (works in editor, fails in packaged build, sessions don’t show, or can’t be found). The solution that found most sucess is to use the Steam Sockets plugin, in order to make sessions visible: - First, enable Steam Sockets - Then, in DefaultEngine.ini, swap the net driver: ```auto [/Script/Engine.GameEngine] +NetDriverDefinitions=(DefName="GameNetDriver", DriverClassName="SocketSubsystemSteamIP.SteamNetDriver", DriverClassNameFallback="OnlineSubsystemUtils.IpNetDriver") ``` - Finally, replace instances of “SteamNetConnection” with “SteamSocketsNetDriver” - Remember to test in Dev packaged builds first For further details regarding the scenario, please check the related thread below: > [@Is there anyone who can run the Online Subsystem Steam properly in UE 5.6?](https://forums.unrealengine.com/t/is-there-anyone-who-can-run-the-online-subsystem-steam-properly-in-ue-5-6/2543935): > > 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… ---
**Author:** ![UnemploydChicken](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@UnemploydChicken](https://forums.unrealengine.com/u/UnemploydChicken)\ **Post date:** [September 19, 2025, 2:59pm UTC](https://forums.unrealengine.com/t/steam-online-subsystem-not-working-in-packaged-build-ue5-6/2652620/4 "2025-09-19T14:59:15Z")
Hey! For anyone running into this issue, I followed the steps by @brs-sebascova above. The result was that my listen server would kick me out of the session the second it loaded me into the map. After further investigating, brs-sebascova worked for me except the the “swap net driver block”. Instead add this: [/Script/Engine.GameEngine] !NetDriverDefinitions=ClearArray +NetDriverDefinitions=(DefName=“GameNetDriver”,DriverClassName=“/Script/SteamSockets.SteamSocketsNetDriver”,DriverClassNameFallback=“OnlineSubsystemUtils.IpNetDriver”) For some reason, my build needed the /Script/SteamSockets.SteamSocketsNetDriver. Unreals [official docs](https://dev.epicgames.com/documentation/en-us/unreal-engine/using-steam-sockets-in-unreal-engine) have you putting the Steam socket as both the Driver Class and the Fallback. I found that if you intend to fallback to NULL, then that implementation fails. Instead I used the OnlineSubsystem allowing the NULL connection to work as the backup. ---
**Author:** ![Soulth\_Stealer](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Soulth\_Stealer](https://forums.unrealengine.com/u/Soulth_Stealer)\ **Post date:** [December 6, 2025, 11:48am UTC](https://forums.unrealengine.com/t/steam-online-subsystem-not-working-in-packaged-build-ue5-6/2652620/5 "2025-12-06T11:48:32Z")
Hello ı watched a video and it worked [https://www.youtube.com/watch?v=UEivY0QcGsc](https://www.youtube.com/watch?v=UEivY0QcGsc) just go to your game’s package folder and find binaries in win64 create a text folder named steam\_appid and enter 480 in it. Have a great day