Getting Subsystem Null to run?

Hi there.

First, my Target:
Since i wanna tryout different replication methods and get into Network functionality, i wanted ro create a simple Create/Join Session Project and tryout the Variable and Function replications.
Cause i‘m not owning a second PC/Laptop and therefor can‘t tryout the systems with Steam, i need to do that locally on one Machine with multiple PIE Windows.

The Problem:
I added the Null OSs to the Default ini and made sure to enable the OSs Null Plugin.
Now i was able to Create a Session on Window 1.
But Client 1 (window 2) can‘t find the session. It fires the Success Pin if FindSession, but Result Array is always 0 in Length.
I read about disabling VirtualNetwork box. I‘ve none installed or activated, just my normal Network Adapter.

So my Question:
How to setup a simple tryout OSs Null Project?

pushing this, cause i´m really into giving it up soon…

I tried Session Creation / Joining via LAN, without LAN, via direct IP (console “open ip”)…

My DefaultEngine.ini has:


[OnlineSubsystem]
DefaultPlatformService=Null

My *.build.cs has:


        PublicDependencyModuleNames.AddRange(new string] { "Core", "CoreUObject", "Engine", "InputCore", "OnlineSubsystem", "OnlineSubsystemNull", "OnlineSubsystemUtils" });
        PrivateDependencyModuleNames.AddRange(new string] { "OnlineSubsystem" });

Try to turn off firewall on all your devices if any. If


open IP_ADDRESS

doesn’t work, then it’s definately an issue with your network, someone is blocking connections