From 4.19 to 4.21 - incompatible_unique_net_id

[sivan]

@D3lanK

Note, I am not using steam on my dedicated server, connecting via raw IP, and so client side I removed all steam net definitions in the DefaultEngine.ini

[OnlineSubsystemSteam]
bUseSteamNetworking=false
… other stuff

[/Script/Engine.GameEngine]
!NetDriverDefinitions=ClearArray
NetDriverDefinitions=(DefName=“GameNetDriver”,DriverClassName=“/Script/OnlineSubsystemUtils.IpNetDriver”,DriverClassNameFallback=“/Script/OnlineSubsystemUtils.IpNetDriver”)
+NetDriverDefinitions=(DefName=“DemoNetDriver”,DriverClassName=“/Script/Engine.DemoNetDriver”,DriverClassNameFallback=“/Script/Engine.DemoNetDriver”)

[OnlineSubsystem]
DefaultPlatformService=Steam
… other stuff

DO NOT HAVE
[PacketHandlerComponents]
[/Script/OnlineSubsystemSteam.SteamNetDriver

I then had to hack the engine in PendingNetGame.cpp by commenting out the following line
//Connection->PlayerId = LocalPlayer->GetPreferredUniqueNetId();

WARNING: I have zero clue what other ramifications there are having a default PlayerId, but I know that’s whats happening if you run the game via editor or run the game without the steam client running.

Thanks man! It saved at least a day for me I mean the last line.
I had the same issue with Oculus Online Subsystem, because its UniqueNetID format is not compatible with NULL OSS, and if I removed the format check in GameModeBase::PreLogin() it crashed my Linux server, but if no ID is sent, it works fine with Gamelift btw ID is passed as UNKNOWN similarly when testing from Editor. And Gamelift uses its own PlayerSessionID, so apparently no more problems so far…