Windows desktop app hangs on startup forever when already signed in (stops after settings_ready, shell never visible) #50008

What version of the Codex app are you using?

26.928.2636.0 (Microsoft Store, build 12404). Also reproduced on 26.928.1915.0 (build 12246).
Last working build: 12111 (worked on 2026-09-29 until the update to 12246).

What platform is your computer?

Windows 11 Pro 10.0.26300 x64 (also reproduced on Windows 10 Pro 19045 before upgrading).
i7-11700, 32 GB RAM, RTX 3070. Home Ethernet, no VPN, no proxy (WinHTTP: direct access).

What issue are you seeing?

When the app is cold-started while already signed in, the window stays on a loading spinner forever.
The log always stops at the same point: renderer and settings load in ~2 s, then shell_visible is never reached, and after ~120 s it logs:

client.performance.span name=app_start outcome=failure reason=timeout
marksMs={"renderer_entry_evaluated":1648,"host_services_ready":1685,"renderer_ready":1869,"host_startup_ready":1871.5,"settings_ready":2234.1}

The local app-server (codex.exe) starts and initializes fine, and the durable host connects. Only the renderer shell never appears.

Key finding: if I sign out first (move ~/.codex/auth.json aside), the app opens to the sign-in screen normally. After signing in, the main UI loads and works for the whole session (ran for 9+ hours). The next cold start while signed in hangs again.

What steps can reproduce the bug?

1. Sign in to the Codex desktop app on Windows.
2. Fully quit the app (all ChatGPT.exe processes).
3. Launch it again → hangs on loading indefinitely.

What is the expected behavior?

The app opens to the home screen when launched while signed in.

Things already tried (none helped)

• Cleared Chromium caches (Cache, Code Cache, GPUCache, shader caches)
• Fresh Electron profile (renamed %APPDATA%\Codex\web)
• Removed stale notify / mcp_servers.node_repl entries in config.toml (pointed to deleted runtime folders)
• Cleared stuck threadAssignmentsMigrated: false / pendingThreadAssignmentIds in .codex-global-state.json
• Disabled the codex-app-tools, computer-use and unified-computer-use plugins
• Fresh ~/.codex (renamed the whole folder): only works until the first signed-in cold start
• cli_auth_credentials_store = "file" per support: auth.json is written, still hangs

Additional information

Recurring warnings/errors in failing launches (also present in working sessions, so possibly unrelated):

• fs/readFile → The system cannot find the path specified. (os error 3) ~2 s after start
• fs/readFile requires an environmentId
• sa_server_request_failed ... status=404 url=/tbo?limit=25
• mcp_extension_tool_discovery_failed ... codex-app-tools ... timed out awaiting tools/list after 10s
• Failed to start the Artifact Session host: Unix-socket transport is not available on Windows