Multiplayer Mac can't Find Sessions using Steam

I have a Mac project that lets the user host a game session or join an existing session through Steam using Blueprints. The DefaultEngine.ini file already has the Steam subsystem configuration and is using the temporary 480 app id. But whenever the game is tested using 2 computers, neither of them can find the session created on the other one.

After packaging the game, adding it to the Steam library of 2 Steam accounts in 2 different computers, the Find Sessions node will return an empty array even after setting the max results to 1,000 or so. Also, after launching the game through Steam, the Steam overlay won’t load.

I’ve noticed that the Steamworks version used by the engine (4.12) is 1.32. Considering that the current version is 1.37, should I update it (if so, how)? Could this be the reason why the overlay and game hosting are failing?

I also tried using a plugin called Advanced Session Plugin which in theory can filter the sessions search to find only my game sessions with no success.

Hey ,

I just made an project and ran through building it for Mac and running the game on two computers. I was able to create the session on one and join with the other.

A few things to keep in mind:

Mac will want you to add the project as a “Non-Steam Game”, which you can do in Steam, on the bottom left side of the window.

Also, make sure your DefaultEngine.ini has the settings for Steam:

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

[OnlineSubsystem]
DefaultPlatformService=Steam

[OnlineSubsystemSteam]
bEnabled=true
SteamDevAppId=480

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

As well as make sure that Steam has been setup for UE4 and the engine has been re-compiled with it:

https://docs.unrealengine.com/latest/INT/Programming/Online/Steam/index.html

Ok so the settings also go in the DefaultGame.ini, not only the DefaultEngine.ini.

About the Steam setup where I need to recompile the engine, does this mean downloading the source files and building it from scratch?

The binary should have steam so you don’t need to build from source. You don’t need those settings in DefaultGame.ini only DefaultEngine.ini

Hi there! I’m having problems getting my project, which runs on Steam Online Subsystem, to work on Mac (it can’t find any hosted sessions), but it works fine over 2 Windows PC. I made the changes in DefaultEngine.ini and added it to Steam as well. I think I must be missing a key set up for Mac since it works on PC, could you please let me know what was needed to have Steam multiplayer working for Mac or share the project you made that works for 2 Macs?