Crash when starting Convai session in UE 5.6.1 (Convai 4.0 beta) – audio/STT related?

Unreal Engine Questions
1

Hello,

I am experiencing consistent crashes when using Convai 4.0 with Unreal Engine 5.6.1.

Setup

  • Unreal Engine: 5.6.1

  • Convai Plugin: 4.0.0-beta

  • Character: MetaHuman

  • Playable Character: Third Person Character

  • Convai is attached to the MetaHuman

Initially, everything was working without any crashes. However, after closing and reopening the project, the issue started to occur.

Now, the crash happens when I start the game (Play mode). The system shows “connecting…”, and shortly after that, the engine crashes.

From my observations, the crash seems to be triggered when the Convai session starts, especially during the connection and audio/STT initialization phase.

I also tried to connect the plugin to different projects, but i had the same problem. Normally i followed this tutorial step by step: https://www.youtube.com/watch?v=4fMCKkrfyaA&t=83s

How can i solve this problem?

2

Hello,

Welcome to the Convai Developer Forum!

Could you please share the logs?

3

LoginId:781757d1461d91faf86148825a28ae32
EpicAccountId:889332aebac641139203cf4f6a89c33d

Unhandled Exception: 0xc06d007f

KERNELBASE
UnrealEditor_Convai!__delayLoadHelper2() [D:\a_work\1\s\src\vctools\delayimp\delayhlp.cpp:375]
UnrealEditor_Convai!_tailMerge_convai_client_dll()
UnrealEditor_Convai!UConvaiSubsystem::ToggleSTT() [D:\build\U5M\Sync\LocalBuilds\PluginTemp\HostProject\Plugins\ConvAI\Source\Convai\Private\ConvaiSubsystem.cpp:1130]
UnrealEditor_Convai!UConvaiPlayerComponent::UnmuteStreamingAudio() [D:\build\U5M\Sync\LocalBuilds\PluginTemp\HostProject\Plugins\ConvAI\Source\Convai\Private\ConvaiPlayerComponent.cpp:817]
UnrealEditor_Convai!UConvaiPlayerComponent::StartSession() [D:\build\U5M\Sync\LocalBuilds\PluginTemp\HostProject\Plugins\ConvAI\Source\Convai\Private\ConvaiPlayerComponent.cpp:743]
UnrealEditor_Convai!UConvaiPlayerComponent::OnServerConnectionStateChanged() [D:\build\U5M\Sync\LocalBuilds\PluginTemp\HostProject\Plugins\ConvAI\Source\Convai\Private\ConvaiPlayerComponent.cpp:868]
UnrealEditor_Convai!UConvaiPlayerComponent::execOnServerConnectionStateChanged() [d:\build\U5M\Sync\LocalBuilds\PluginTemp\HostProject\Plugins\ConvAI\Intermediate\Build\Win64\UnrealEditor\Inc\Convai\UHT\ConvaiPlayerComponent.gen.cpp:646]
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_Convai!TMulticastScriptDelegate::ProcessMulticastDelegate() [D:\RocketSync\5.6.0-43139311+++UE5+Release-5.6\Working\Engine\Source\Runtime\Core\Public\UObject\ScriptDelegates.h:929]
UnrealEditor_Convai!FOnServerConnectionStateChangedSignature_DelegateWrapper() [d:\build\U5M\Sync\LocalBuilds\PluginTemp\HostProject\Plugins\ConvAI\Intermediate\Build\Win64\UnrealEditor\Inc\Convai\UHT\ConvaiSubsystem.gen.cpp:74]
UnrealEditor_Convai!UConvaiSubsystem::OnConnectedToServer'::2’::<lambda_1>::operator()() [D:\build\U5M\Sync\LocalBuilds\PluginTemp\HostProject\Plugins\ConvAI\Source\Convai\Private\ConvaiSubsystem.cpp:1315]
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_RenderCore
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
kernel32
ntdll

[2026.04.04-14.47.24:222][271]LogLoad: Game class is ‘BP_ThirdPersonGameMode_C’
[2026.04.04-14.47.24:237][271]LogWorld: Bringing World /Game/ThirdPerson/Maps/UEDPIE_0_ThirdPersonMap.ThirdPersonMap up for play (max tick rate 0) at 2026.04.04-17.47.24
[2026.04.04-14.47.24:238][271]LogWorld: Bringing up level for play took: 0.015059
[2026.04.04-14.47.24:240][271]LogOnline: OSS: Created online subsystem instance for: :Context_6
[2026.04.04-14.47.24:245][271]ConvaiChatbotComponentLog: Auto Initializing Session
[2026.04.04-14.47.24:245][271]ConvaiSubsystemLog: ConvaiClient Version: 0.1.3
[2026.04.04-14.47.24:245][271]ConvaiDefinitionsLog: End User ID not provided, using Device ID: 00303ae1-0040-4631-b5b0-b56020442e5a
[2026.04.04-14.47.24:251][271]ConvaiConnectionManagerLog: Character [79b0adfa-2ad8-11f1-8736-42010a7be02c]: New connection established successfully
[2026.04.04-14.47.24:251][271]ConvaiChatbotComponentLog: Session started for character ID: 79b0adfa-2ad8-11f1-8736-42010a7be02c
[2026.04.04-14.47.24:251][271]ConvaiFaceSyncLog: LipSyncTimeOffset: -0.030000s
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: Connecting to Convai service with parameters:
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: StreamURL: https://realtime-api.convai.com/connect
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: CharacterID: 79b0adfa-2ad8-11f1-8736-42010a7be02c
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: ConnectionType: audio
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: LLMProvider: dynamic
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: BlendshapeProvider: neurosync
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: BlendshapeFormat: mha
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: EmotionProvider: nrclex
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: EndUserID: 00303ae1-0040-4631-b5b0-b56020442e5a
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: EndUserMetadata:
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: ChunkSize: 10
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: OutputFPS: 60
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: FramesBufferDuration: 0.000000
[2026.04.04-14.47.24:252][271]ConvaiSubsystemLog: InvocationMetadata - ExtraMetadata: {
“convai_plugin_version”: “4.0.0-beta.14”,
“platform”: “Windows”,
“ue_version”: “5.6.1-44394996+++UE5+Release-5.6”,
“app_name”: “Artemis_outside_f”,
“convai_client_version”: “0.1.3”
}
[2026.04.04-14.47.24:256][271]PIE: Server logged in
[2026.04.04-14.47.24:258][271]PIE: Play in editor total start time 0,109 seconds.
[2026.04.04-14.47.28:080][713]ConvaiSubsystemLog: OnConnectedToServer called
[2026.04.04-14.47.28:080][713]ConvaiReferenceAudioThread: ConvaiReferenceAudioThread created with chunk size: 480
[2026.04.04-14.47.28:082][713]ConvaiReferenceAudioThread: ConvaiReferenceAudioThread initialized
[2026.04.04-14.47.28:082][713]ConvaiReferenceAudioThread: ConvaiReferenceAudioThread started running
[2026.04.04-14.47.28:082][713]ConvaiReferenceAudioThread: Reference audio capture started
[2026.04.04-14.47.28:082][713]ConvaiSubsystemLog: Started reference audio capture thread
[2026.04.04-14.47.28:085][713]ConvaiChatbotComponentLog: OnConnectedToServer
[2026.04.04-14.47.30:831][ 42]ConvaiSubsystemLog: :electric_plug: Attendee connected: convai-bot

4

In the latest update published on FAB, DLLs originating from FAB are not being imported correctly.
As a workaround for now, you can download the latest version from the GitHub releases page: https://github.com/Conv-AI/Convai-UnrealEngine-SDK-V4/releases
In your project’s root directory, create a Plugins folder if it does not already exist, then copy the Convai plugin from the downloaded package into that folder and test again.

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