Windows desktop app crashes when in-app Browser route is torn down (5 reproducible crashes)

Summary

The Codex desktop app for Windows repeatedly crashes when an in-app Browser / browser-use session is closed after its route becomes unavailable.

Five app-level crashes occurred on the same day. Every Crashpad sidecar reports:

{"capture_kind":"crash","osarch":"x86_64","ptype":"browser"}

Environment

• Codex desktop app: 26.825.6671.0
• OS: Windows x64
• Time zone: Asia/Shanghai

Crash times

• 2026-09-01 11:41:47
• 2026-09-01 12:06:28
• 2026-09-01 15:22:35
• 2026-09-01 15:38:42
• 2026-09-01 16:01:13

The app restarted successfully after each crash. Windows Application/System event logs did not show a system restart or a separate OS-level failure.

Repeated log sequence

Immediately before the crashes, the desktop logs repeatedly show:

No ChatGPT browser route is available for browser session <conversation-id>
IAB_LIFECYCLE unregistered debugger listener ... reason=target-close
IAB_LIFECYCLE browser sidebar guest torn down
IAB_LIFECYCLE renderer removed browser sidebar webview
IAB_LIFECYCLE closed browser sidebar page
IAB_LIFECYCLE iab rejected tab for route ... tabRouteKey=null

The Crashpad report is then created within roughly one second of the browser target/webview teardown.

Reproduction pattern

1. Run a Codex task that uses the in-app Browser for visual verification or a web form.
2. Let the task create/open an in-app browser-use page.
3. The app reports that no ChatGPT browser route is available.
4. When the browser target closes and the webview is torn down, the desktop app crashes.
5. After restarting Codex, resuming a browser-using task can reproduce the issue.

The issue appeared more frequently when two tasks were using the in-app Browser concurrently, but one particular long-running browser-using task was present immediately before all five crashes.

Expected behavior

A missing/stale browser route or browser tab teardown should fail the tool call or close the tab without terminating the desktop app.

Actual behavior

The Codex desktop browser process crashes and all active tasks are interrupted.

Additional information

The full local logs and affected session transcripts may contain sensitive project information, so they are not attached publicly. They can be shared privately with OpenAI if needed.

Start with the repeated desktop log sequence around the unavailable browser route, debugger listener cleanup, guest teardown, and webview removal. Trace the browser target and tab teardown path, including concurrent browser-use tasks, and verify that a missing or stale route closes the tab or rejects the tool call without crashing the app.