Codex App window exits when opening or resuming threads after auth_token_missing / browser pane initialization

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

26.818.2872.0

What subscription do you have?

ChatGPT Pro x20

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

On Codex App for Windows, opening or resuming a thread can make the primary Electron window disappear. There is no Windows Application Error, WER report, or crash dump.

The app logs show this sequence:

1. thread/read and thread/resume succeed.
2. A Browser Use host is created for the thread route (browserPane=true).
3. The route window becomes unavailable (route window is not live, hasWindowState=false).
4. Authentication falls back to auth_token_missing / HTTP 401 (Missing valid access token or actor biscuit / Unauthorized).
5. IPC fails with EPIPE, then the app server stops with stop_process.

The issue reproduced repeatedly on the same day after reset, reinstall, and reboot, including with both old and newly created threads. Local thread rollouts and SQLite databases pass integrity checks, so this does not appear to be corruption of one conversation.

This may be related to #35740 / #35352, but there is no GPU process crash line in these logs, so I cannot confirm the same root cause.

What steps can reproduce the bug?

1. Start Codex App on Windows.
2. Open an existing thread, or create a new thread and navigate to it.
3. The thread initially opens/resumes successfully.
4. Within a few seconds, the main Codex window disappears.

Troubleshooting already performed:

• Reinstalled the same Codex App version and rebooted Windows.
• Verified JSON/JSONL state and SQLite databases; no corruption found.
• Removed an old UTF-8 BOM from config.toml; TOML parsing succeeds.
• Disabled features.computer_use, features.browser_use, and browser/computer-use plugins as a reversible diagnostic.
• Ran codex exec --strict-config --ephemeral; configuration and ChatGPT authentication both succeeded.
• The desktop app partially restored some browser/computer-use settings on startup, and navigating to a thread still reproduced the exit.

No local chat history or databases were deleted.

What is the expected behavior?

Opening or resuming a thread should keep the Codex window and app server running. If authentication expires, the app should show a recoverable sign-in error instead of losing the renderer/window and terminating the app server.

Additional information

Observed on Codex App 26.818.2872.0, Windows x64.

GitHub suggests #32040 as a potential duplicate. That issue covered Windows exits during in-app Browser/PiP initialization and was closed as fixed on July 17, 2026. The current reproduction is on the newer 26.818.2872.0 build, so it may be a regression. In this case, opening or resuming ordinary threads creates a browser-pane host and is followed by route-window loss, repeated auth_token_missing / HTTP 401 errors, EPIPE, and app-server stop_process.

A closely related report is #35740 (closed as duplicate of #35352). There is no explicit GPU-process crash line in the current logs, so I cannot confirm the same root cause.

no-active-thread-01a02047-94cd-7431-ad37-248f5a8d4ef4

Start by tracing the reported thread/read and thread/resume flow through Browser Use host creation and the route-window state logs. Reproduce on Windows with an existing or new thread, then follow the auth_token_missing, HTTP 401, EPIPE, and stop_process sequence. Done means opening or resuming a thread keeps the Electron window and app server running, with authentication failures shown as recoverable errors.