Windows ChatGPT Desktop 26.715.x cannot send messages after July 18 update, previous Codex conversations become empty, "unknown conversation" in logs

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

Powered by Codex & OWL Version: 26.715.31925

What subscription do you have?

ChatGPT Go

What platform is your computer?

Windows 11 x64

What issue are you seeing?

After updating to ChatGPT Desktop 26.715.x (July 18 release), both Chat and Codex became unusable.

Current behavior:

• The application launches normally.
• Login succeeds.
• Conversation history is displayed.
• Sending any message shows "Thinking..." for about 30 seconds.
• The app then starts reconnecting repeatedly and finally times out.
• ChatGPT Web works normally using the same account and the same network.

In addition, all previous Codex conversations are broken.

The conversation list is still visible, but opening any previous conversation displays an empty page.

This started immediately after updating around July 18.

Relevant log messages:
Failed to generate thread title
Timed out waiting for structured result.

Received turn/completed for unknown conversation

I also observed repeated 30-second request timeouts in the logs.

What steps can reproduce the bug?

1. Open ChatGPT Desktop (26.715.31925).
2. Open any existing Codex conversation.
3. The conversation page is empty even though the conversation still exists in the sidebar.
4. Create a new conversation.
5. Send any prompt (for example: "hello").
6. The UI shows "Thinking..." for about 30 seconds.
7. The app starts reconnecting repeatedly.
8. Eventually the request times out.

The issue reproduces every time (100%).

What is the expected behavior?

Existing Codex conversations should load normally.

• Sending a message should immediately receive a streamed response.
• The Desktop app should behave the same as the ChatGPT web experience.

Instead, previous conversations appear empty and every new request gets stuck in "Thinking...", then reconnects indefinitely before timing out.

Additional information

Additional information:

• Windows 11
• ChatGPT Web works normally.
• The issue only affects the Desktop application.
• WinHTTP proxy: Direct access (no proxy server)
• No HTTP_PROXY / HTTPS_PROXY / ALL_PROXY environment variables
• Cleared %LOCALAPPDATA%\OpenAI and reinstalled the application

-The "Received turn/completed for unknown conversation" log entry appears to correlate with previous conversations becoming empty. It seems the Desktop client loses the local conversation state while the conversation metadata (sidebar entries) is still present.