Crash when using Multiplayer in Unreal Engine

Unreal Engine Bugs
1 
[2025.08.26-20.21.57:468][232]LogWindows: Error: appError called: Assertion failed: IsInGameThread() [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\NetDriver.cpp] [Line: 7628] 
Attempted to call ProcessRemoteFunction from a thread other than the game thread, which is not supported.  Object: /Game/TestProject/Maps/lvl_main.lvl_main:PersistentLevel.BP_character_C_1.ConvaiChatbot Function: Broadcast_onResponseDataReceived

I get this crash when using multiplayer in Unreal Engine 5.5. It happens when receiving the character’s response.

2

I’ve tested multiple versions of the Unreal plugin, and it looks like this bug was introduced in 3.5.4-hotfix-1 and is there in all newer versions. I had to revert back to 3.5.3-beta to get multiplayer to work.
Would really appreciate if someone can look into this.
Thanks

3

Hello @sirtapps,

Could you please share the logs?

4

Seems like 3.6.7 has fixed the crash.

5

Yes, we have released a fix for this.

Crash in UConvaiChatbotComponent::onResponseDataReceived when replicated