UE 5.5 / 5.4 – Instant crash after pressing T (Push‑to‑Talk) with Convai SDK 3.6.2

Unreal Engine Questions
,
1

Hi everyone,

I’ve run into a brick wall and hope somebody can spot what I’m missing. Until last night (Friday 26 July, about 17:00 CET) my project ran flawlessly. This morning, first thing around 10:00, it started crashing the moment I press T to start talking to my Convai character.

Nothing in the project changed overnight: no code edits, no new assets, no engine upgrade. Yet now the editor (and a packaged build) just dies two seconds after the key‑press with a Fatal Error! dialog.

What I see in the log (excerpt)

[2025.07.26‑11.32.46:733] ConvaiSubsystemLog: gRPC Creating Channel...
[2025.07.26‑11.32.53:776] ConvaiSubsystemLog: Warning: gRPC channel not ready yet. Current State: GRPC_CHANNEL_IDLE
[2025.07.26‑11.32.55:045] LogWindows: FPlatformMisc::RequestExit(1, ...)

I’ve repeated the launch half a dozen times and the pattern is identical—GRPC_CHANNEL_IDLE pops up, then the engine shuts itself down.

Technical details (for the curious)

  • System: Windows 11 24H2 – i9‑13980HX / RTX 4090 Laptop / 64 GB RAM
  • Unreal Engine: 5.5.4
  • Convai plugin: 3.6.2
  • Character ID: 09f85624-eea8-11ef-85b7-42010a7be016
  • Subscription: plenty of credits remaining
  • Launch flags: -log plus environment vars GRPC_TRACE=client_channel,api & GRPC_VERBOSITY=DEBUG (the release build prints no extra gRPC trace)
  • Last known good run: Friday 26 July 2025, 17:00 CET
  • First failing run: Saturday 26 July 2025, 10:00 CET

If anyone has bumped into the same GRPC_CHANNEL_IDLE behaviour today, or knows a workaround to kick the channel out of idle, I’d really appreciate your insight. Thanks in advance!

2

Hello @omar.venturi,

Could you please share all the logs?

3

Sure… here they are
DAnnunzio_20250726_130806.log (630 Bytes)
DAnnunzio.log (199.8 KB)

4

Hi @K3,

Just checking in for an update—do you have any feedback regarding my issue?
Is this crash with GRPC_CHANNEL_IDLE a known bug, or am I the only one experiencing it at the moment?

I need to report back to my client, so any news (even if it’s just “we’re investigating”) would be very helpful.

Thanks again for your support!

5

This crash should not be caused by the GRPC_CHANNEL_IDLE. We haven’t encountered this issue before, so it’s not a known bug at the moment. Since it’s the weekend, our team will begin investigating it starting next week. We appreciate your patience.

6

I’ve just sent a video of a step by step execution in UE where error occurs in Start Talking node in ConvaiBasePlayer.
Thanks

7

Hi everyone,

Just following up: since no changes were made on our side, the application started working again around the same time on two completely separate environments (development and production).

At present, everything is up and running without intervention related to this specific problem. We have not yet identified the root cause, but there have been no further crashes in either environment.

Thank you @K3 and the Convai team for looking into this. Unless new information emerges, I suggest we consider this issue closed on our end. If others encounter the same behavior, please feel free to share your logs and setup so the Convai team can investigate further.