Server sends unrecognized RTVI packet types — plugin logs "Client version unknown" — UE5.8, 4.0.0-beta.24

What do you need help with?

Bug report

Installation method

FAB

Issue area

Connection / WebRTC

Impact

Major - a core flow is broken

Unreal Engine version

5.8.0

Convai Unreal Engine Plugin version

4.0.0-beta.24

Character ID

beb216d2-4fbd-11f1-a19e-42010a7be02e

Session ID

8fe58bd5-dca7-49c5-ae06-c51ac3b37a4e

Project setup

Blueprint

Target platform

Unreal Editor

Where does it happen?

Custom project

Short summary

Server sends unrecognized RTVI packet types (final-user-transcription, interaction-created, bot-turn-completed) — plugin logs "Client versio

What happened?

Immediately after connecting, the server responds with “Client version unknown. Compatibility issues may occur.” and subsequently sends packet types the plugin’s parser does not recognize, including ‘final-user-transcription’, ‘interaction-created’, and ‘bot-turn-completed’. This appears to break end-of-utterance detection: the client correctly receives and displays interim (final:false) user-transcription chunks, but never receives a recognized signal marking the utterance as complete — leading to fragmented conversation turns and inflated interaction counts (a single utterance is sometimes counted as 4-5 interactions).

Connection metadata shows:
“convai_plugin_version”: “4.0.0-beta.24”
“convai_client_version”: “0.1.26.1+fdeec72”

The bot identifies itself as running:
{“data”:{“about”:{“library”:“pipecat-ai”,“library_version”:“1.5.0”},“version”:“2.0.0”},“type”:“bot-ready”}

Questions:

  1. Is 4.0.0-beta.24 genuinely compatible with the current backend protocol version (pipecat-ai 1.5.0 / RTVI 2.0.0)?
  2. Is there a newer plugin build that correctly parses these packet types?
  3. Given this affects interaction counting/billing, is there a workaround in the meantime?

What did you expect?

I expected the client to correctly recognize and process all packet types sent by the server, including ‘final-user-transcription’, ‘interaction-created’, and ‘bot-turn-completed’. Specifically, I expected:

  1. No “Client version unknown” error on connection — the plugin version (4.0.0-beta.24) should be recognized as compatible with the current backend protocol (pipecat-ai 1.5.0 / RTVI 2.0.0), or the plugin should be updated to match it.

  2. A single continuous utterance (with natural pauses) to be treated as one complete user turn, based on the server’s authoritative ‘final-user-transcription’ signal — not fragmented into multiple turns due to the client falling back to local VAD timing alone.

  3. The interaction counter to accurately reflect the actual number of conversational exchanges

Unreal logs or error messages

LogWindows: File ‘aqProf.dll’ does not exist
LogProfilingDebugging: Loading WinPixEventRuntime.dll for PIX profiling (from ../../../Engine/Binaries/ThirdParty/Windows/WinPixEventRuntime/x64).
LogWindows: Failed to load ‘VtuneApi.dll’ (GetLastError=126)
LogWindows: File ‘VtuneApi.dll’ does not exist
LogWindows: Failed to load ‘VtuneApi32e.dll’ (GetLastError=126)
LogWindows: File ‘VtuneApi32e.dll’ does not exist
LogWindows: Started CrashReportClient (pid=30656)
LogWindows: Custom abort handler registered for crash reporting.
LogInit: Running DelayedAutoRegister Phase StartOfEnginePreInit
LogInit: Display: Running engine for game: Elaris
LogCore: UTS: Unreal Trace Server launched successfully
LogTrace: Initializing trace…
LogCore: Display: Requested channels: ‘cpu,gpu,frame,log,bookmark,screenshot,region’
LogCore: No trace connection. Tracing to in-memory cache.
LogTrace: Display: Control listening on port 36466
LogTrace: Finished trace initialization.
LogCsvProfiler: Display: Metadata set : platform=“Windows”
LogCsvProfiler: Display: Metadata set : config=“Development”
LogCsvProfiler: Display: Metadata set : buildversion=“++UE5+Release-5.8-CL-55116800”
LogCsvProfiler: Display: Metadata set : engineversion=“5.8.0-55116800+++UE5+Release-5.8”
LogCsvProfiler: Display: Metadata set : enginereleaseversion=“5.8.0”
LogCsvProfiler: Display: Metadata set : os=“Windows 11 (25H2) [10.0.26200.8875] "
LogCsvProfiler: Display: Metadata set : cpu=“AuthenticAMD|AMD Ryzen 7 PRO 5845 8-Core Processor”
LogCsvProfiler: Display: Metadata set : pgoenabled=“0”
LogCsvProfiler: Display: Metadata set : pgoprofilingenabled=“0”
LogCsvProfiler: Display: Metadata set : ltoenabled=“0”
LogCsvProfiler: Display: Metadata set : asan=“0”
LogCsvProfiler: Display: Metadata set : mergedmodules=“0”
LogCsvProfiler: Display: Metadata set : compacttset=“0”
LogCsvProfiler: Display: Metadata set : commandline=”" “C:/Users/Mariusz/Documents/Unreal Projects/UE_5.8_Elaris_28.07.2026_o2/Elaris.uproject” -AUTH_LOGIN=unused -AUTH_PASSWORD=0b8f7085f7c7483e9f46a9ebca640d81 -AUTH_TYPE=exchangecode -epicapp=UE_5.8 -epicenv=Prod -EpicPortal -epicusername=mariusz77904 -epicuserid=252e385ac2ce48f79201382695709e14 -epiclocale=pl -epicsandboxid=ue""
LogCsvProfiler: Display: Metadata set : loginid=“11d8b140409b060b46c3c4bebeeb6023”
LogCsvProfiler: Display: Metadata set : llm=“0”
LogModuleManager: InternalLoadLibrary: ‘StorageServerClient’ ('C:/Program Files/Epic Games/UE_5.8/Engine/Binaries/Win64/UnrealEditor-Storag

Screenshots, recording, logs, or minimal repro

logi 28072026.pdf (3.32 MB)

I checked the relevant documentation, resources, and similar forum posts before posting.

on

I confirm that I did not include API keys, tokens, passwords, secrets, private character data, private conversation logs, or customer data.

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Is this a blocker issue?