PIE client disconnect in 5.6.1 when connecting to non-PIE uncooked server

Development Programming & Scripting Multiplayer & Networking
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1

After updating from 5.5 to 5.6.1 it seems that connecting a standalone PIE client to a local non-PIE uncooked server fails with WP levels. During level load the client is disconnected with a missing level message like-

[2026.01.29-15.30.24:924][321]LogNet: UNetConnection::SendCloseReason:
[2026.01.29-15.30.24:925][321]LogNet:  - Result=MissingLevelPackage, ErrorContext="/Memories,/Memory/UEDPIE_0_MAP_Activities_NPC_TestingMap_B9QEWU4LFSTZ92Z9XQ7CU2VA5"

This worked in 5.5. It still works with non WP levels. We don’t have this issue running both client and the server under PIE with server as a separate process, nor with a non PIE client connecting to the server, so speculating whether this is a WP PIE->non PIE compatibility issue in 5.6?

Regards,

Alistair

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2

Steps to Reproduce

  1. Start an uncooked server on a WP level
  2. Start a standalone PIE client and connect to the server
  3. Client will disconnect with MissingLevelPackage error

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3

Hi,

We’ve received [some similar [Content removed] in the past, so to get a better idea of the problem, I have a couple of questions.

First, are you using server side streaming (wp.Runtime.EnableServerStreaming and wp.Runtime.EnableServerStreamingOut)?

Also, what are the values for LevelStreaming.DefaultAllowClientUseMakingVisibleTransactionRequests, LevelStreaming.DefaultAllowClientUseMakingInvisibleTransactionRequests, LevelStreaming.ShouldServerUseMakingVisibleTransactionRequest, wp.Runtime.UseMakingVisibleTransactionRequests, and wp.Runtime.UseMakingInvisibleTransactionRequests in your project?

Do you have any other non-default configs around replication and world partition?

Finally, I just want to clarify exactly how you’re starting the client and server instances. In this case, is the server is still an editor process, such as those started from the command line or by using the “Standalone Game” play mode?

Thanks,

Alex

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4

Hi Alex,

Thanks for your reply. We don’t have server streaming enabled, nor any of those other CVars - I just tried toggling them to see if it make a difference but consistently saw the same problem. I don’t believe we have any non-standard configs around replication & wp. This is using RepGraph.

Starting the client through the PIE in standalone mode, and the server from the commandline: UnrealEditor.exe <path_to_uproject> -server -log

Hope this information is helpful,

Alistair

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5

Hi,

I see, thank you for the additional information.

Are you able to reproduce this issue in Lyra?

Also, could you provide server and client logs from when the disconnect occurs, with increased verbosities for the LogNet, LogReplicationGraph, LogLevelStreaming, and LogPlayerController categories?

Thanks,

Alex

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