What do you need help with?
Bug report
Installation method
Manual installation / GitHub
Issue area
Build / Packaging
Impact
Blocker - I cannot continue
Unreal Engine version
5 8 0
Convai Unreal Engine Plugin version
4 0 0 beta 25 1
Project setup
Blueprint
Target platform
Windows build
Where does it happen?
Custom project
Short summary
Unreal application crashes during Convai idle disconnect with a ReferenceAudioThread array out-of-bounds assertion
What happened?
We are experiencing an intermittent but reproducible crash in our packaged Unreal Engine application during Convai’s automatic idle disconnect.
The idle disconnect itself is expected. After a period of inactivity, Convai disconnects the session from the server. We have implemented an auto-reconnect Blueprint that monitors the Convai Chatbot Connection State and calls Start Session again when the state remains Disconnected.
This reconnection logic works normally and is not the issue we are reporting.
The problem is that, on some idle disconnects, the entire Unreal application crashes during the Convai disconnect / reference audio cleanup sequence.
We captured two separate crashes with the same Unreal assertion:
Assertion failed:
(Count >= 0) & (Index >= 0) & (Index + Count <= ArrayNum)
Array range out of bounds:
index 0 and length 480 into an array of size 0
Immediately before the crash, the Unreal log contains Convai reference audio cleanup messages, including:
ConvaiReferenceAudioThread: Warning: Reference audio capture not active
ConvaiSubsystemLog: Stopped and cleaned up reference audio capture thread
The corresponding Convai logs show the automatic idle disconnect and reference audio shutdown at the same time.
We also noticed that the Convai ReferenceAudioThread is created with a chunk size of 480, while the crash attempts to access exactly 480 elements from an array whose size is 0.
This may indicate a race condition during the reference audio teardown, where
Screenshots, recording, logs, or minimal repro
UE_TradeshowAvatar2-backup-2026.08.06-09.22.13.log (2.35 MB)ConvAI_TradeshowAvatar2_20260806_085346_Default.log (2.17 MB)ConvAI_TradeshowAvatar2_20260807_170837_Default.log (886 KB)UE_TradeshowAvatar2.log (664 KB)
I checked the relevant documentation, resources, and similar forum posts before posting.
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