Trying to use the new "Create Session" node fails

The output logs show: “Invalid or uninitialized OnlineSubsystem” and then on the next line, “Cannot map local player to unique net ID”

I’m using a fresh copy of the 3rd-person game template, with just my CreateSession added into a custom GameInstance class.

Here’s my blueprint setup. I have my character set up to call the HostSession event when I press a key. (I tried “Use LAN” both checked and unchecked, so that’s not the problem.)

I posted a question on the answerhub here: When I try to use the new "Create Session" node, it fails - Multiplayer & Networking - Unreal Engine Forums

Okay, so it works now if I do Play-In-Editor, but if I launch it as a standalone or packaged version it gives the failure message. Any ideas?

I’ve been getting no love from the bp sessions in packaged builds either :’(

[Answerhub woes]

The Epic team is back in the office tomorrow, maybe they’ll shed some light on this.

Same issue here.
I tried editing the file at mygame\Saved\Config\Windows\Engine.ini
to have

[OnlineSubsystem]
DefaultPlatformService=Steam

But to no avail.

Sooo… anybody found a solution yet? I’m still stumped.

Hey guys,

I responded to gregdumb’s question on AnswerHub, but the problem seems to be a missing DefaultPlatformService value.

This is close, but the ini file in the Saved directory will get overwritten. Try changing mygame\Config\DefaultEngine.ini instead. Also, for Steam you need some additional configuration options in the ini. See Online Subsystem Steam Interface in Unreal Engine | Unreal Engine 5.3 Documentation

I’ll look into this too and reply on AnswerHub.

I solved it, in my Build.cs I needed to add “OnlineSubsystemNull” to my dependencies. (This was for my c++ project, the 3rd person template seems to have fixed itself.)

The blueprint nodes don’t seem to work at the moment for the default “built in” subsystem and there is no “Build.cs” file anywhere in the solution. The best solution is to add your own subsystem, there are many good ones out there. Most people use Steam and use the Spacewar app id for testing

Even though some online subsystems are provided with the engine, currently you’ll still need to add

[OnlineSubsystem]
DefaultPlatformService=Null

to your engine config .ini file (usually Config/DefaultEngine.ini) in order to use a subsystem by default and load it at runtime. You can also substitute “Null” for “Steam” or the subsystem for another platform.

Is your project content-only? A Build.cs file for your project would only exist if it contains C++, and it’ll actually be named <ProjectName>.Build.cs.

If the DefaultPlatformService value is set and the nodes still aren’t working, if you can provide your log output we can try to figure out what’s going on.