Invalid or uninitialized OnlineSubsystem

Hi everybody i’m trying to make an online system for my game based on a lobby where people can join each other and play the game, but when i do “Find Session” or “Create Session” there is an error log message

LogScript:Warning: FindSessions - Invalid or uninitialized OnlineSubsystem
LogScript:Warning: FindSessions - Cannot map local player to unique net ID

While i had added
PublicDependencyModuleNames.AddRange(new string[] { “Core”, “CoreUObject”, “Engine”, “OnlineSubsystem” }); into my build.cs file game
and also
[OnlineSubsystem]
DefaultPlatformService=LAN into my DafaultEngine.ini

Can someone knew how to fix that ?
Here’s a part if my bluprint

Thank you

did u find any solution of this?

I don’t remeber well but, for the onlineSubsystem i remplaced it by, OnlineSubsystemNull, same in the DefaultEngine.ini DefaultPlatformService=Null and it worked

Thank you !!!