[REQUEST] Fix SteamNetDriver UE 4.27.2 up to UE 5.1 or feature to downgrate project to 4.26.

I have a serious problem, in version 4.27.2 to 5.1 the Steam Sessions do not work, Create session able to be connectable only with SteamSockets plugin enabled (DefaultEngine.ini reconfigured for each case), Find sessions returns 0 if “Use LAN” option is disabled, In the steam server list, the server only appears in the “LAN” tab, in the internet tab it does not appear. I tested everything with open ports 27015, dedicated server reconfigured to -port 27015, ports on modem/windows, nothing. That’s it, it doesn’t work anymore, I’ve gone all over the internet and everyone from version 4.27 to 5.1 onwards has the same problem, I read about the steamCore plugin, the same problem appears in version 5.1.

Apparently the listening server through steam from version 4.27 to 5.1 has stopped working, the default system OnlineSubsystemSteam has been broken as it creates a non-connectable session, and changed to SteamSockets which has the limitation of the steam server being only locally connectable.

I couldn’t find any documentation on how to manually setup the new SteamSockets system and create sessions and connect through that.

I couldn’t find a feature to downgrade the project and all content to version 4.26 where it still worked.

Same problem… I’ve finished my game about 3 months ago but I couldn’t publish. I’ve tried everything (Source Version, Different Ports, Disable net.Verify cvars, Changing Socket Drivers…) Since I don’t know much about network sockets, I don’t want to change any engine code. I’m just waiting next engine update :frowning:


Please everyone reading this, vote for this at the top. This issue is preventing multiplayer indie games from being completed and published to Steam. Someone at Epic Games needs to look into this.


uno1982/UE4.27_OnlineSubsystemSteamFix: Fix to issues with UE4.27.2 binary engine module (github.com)

I hope this finds you guys well and helps you along the way :slight_smile:

Place this in your project/plugins folder along side advanced sessions 4.27 locked.
Use the create advanced sessions and find advanced sessions nodes with “use lobbies if available bool” apply the SystemSeetings for net.AllowClientREmapCacheObject=1 and net.FilterGuidREmapping=0 if your using seamless server travel to avoid netGuid desync errors.

Not necessary because unreal header will build the plugins for you but if you haven’t setup visual studio and c++ prereqs here is a video to help with that too.

Happy Developing :slight_smile: