Still reproducible on Windows Desktop 26.908.40834 — first turn completes, but follow-up message does not create a new turn/start

What version of the Codex App are you using (From “About Codex” dialog)?

26.908.40834

What subscription do you have?

ChatGPT Pro 5x

What platform is your computer?

Windows 11, x64

What issue are you seeing?

On Codex Desktop 26.908.40834 for Windows, the first message in a conversation works normally, but after the first response completes, I cannot send a follow-up message in the same conversation.

The follow-up message does not start a new turn and the conversation becomes effectively unusable for multi-turn interaction.

What steps can reproduce the bug?

1. Open Codex Desktop on Windows.
2. Open a local project/repository.
3. Start a new conversation.
4. Send a simple prompt such as: "Reply with only 1".
5. Wait for Codex to complete the response.
6. In the same conversation, send another prompt such as: "Reply with only 2".
7. The second message does not start normally and no new response is generated.

This is reproducible consistently after the first completed turn.

What is the expected behavior?

After the first response completes, I should be able to continue sending additional messages in the same conversation normally.

Each follow-up message should start a new turn while preserving the existing conversation context.

Additional information

Codex Desktop version: 26.908.4834.0

The first turn reaches the local app-server successfully with method=turn/start and errorCode=null.

However, after attempting to send the second message, no second turn/start is observed in the logs.

The logs also repeatedly contain messages such as:

Received turn/started for unknown conversation

Received turn/completed for unknown conversation

and:

Received broadcast but no handler is configured method=thread-stream-following-changed

The local app-server remains running, and the first request completes successfully, so this appears to be a Codex Desktop renderer/conversation-state issue rather than an authentication, network, or model API failure.

I also observed a separate Git checkpoint warning involving refs/codex/turn-diffs/checkpoints/... with exitCode=128, although this may be unrelated to the follow-up-message issue.

Start by tracing the Windows Desktop renderer's conversation state after the first response and the local app-server turn/start entry point, using the provided reproduction steps and logs. Done means a follow-up message dispatches a new turn, preserves the conversation context, and no longer produces the reported unknown-conversation events.