Codex Desktop conversation can corrupt Windows AppX package state

Reproduce the failure by opening the affected existing conversation and inspect the browser sidebar webview resume path around the logged thread/read, thread/resume, and Conversation state not found events. Verify that stale conversation-local state produces a recoverable error or isolated reset, while the desktop app remains launchable and the Windows AppX package stays healthy without reinstalling.

Summary

Opening one existing Codex Desktop project conversation can crash/disappear the desktop app and leave the Windows AppX package in a broken state. After this happens, the app no longer launches until the local desktop web profile is quarantined and the Microsoft Store package is reinstalled.

This is a critical data/state handling bug: a single stale/corrupt conversation/browser-sidebar state should not be able to poison the whole desktop app or the Windows package launch state.

Environment

• App: OpenAI.Codex / Codex Desktop from Microsoft Store
• Package: OpenAI.Codex_26.721.4979.0_x64__2p2nqsd0c76g0
• Version: 26.721.4979.0
• OS: Windows 10 22H2
• Install source: Microsoft Store product 9PLM9XGG6VKS

Impact

• The app initially opens the existing conversation.
• Shortly after, the desktop app disappears/crashes.
• Windows marks the package as Modified, NeedsRemediation.
• Subsequent launches fail with AppModel error 0x3CFC until reinstall.
• Normal app restart does not recover it.

Expected Behavior

If a conversation's local desktop state, browser sidebar state, or embedded browser session is stale/corrupt, Codex Desktop should handle it gracefully:

• Show a recoverable error for that conversation.
• Allow the user to reset only that conversation's local desktop state.
• Keep the app launchable.
• Never leave the Microsoft Store/AppX package in NeedsRemediation because of one conversation state.

Actual Behavior

Opening the affected existing conversation triggers a browser sidebar/webview restore path, then logs Conversation state not found, then a Chromium GPU child process crash/launch-failure. After this, Windows AppModel reports launch failure and the AppX package state becomes broken.

Relevant Sanitized Logs

Codex Desktop logs around the crash:

IAB_LIFECYCLE registered browser sidebar thread conversationId=<redacted>
IAB_LIFECYCLE renderer created browser sidebar webview ... initialUrl=https://dash.cloudflare.com/login
maybe_resume_started conversationId=<redacted>
response_routed ... method=thread/read
response_routed ... method=thread/resume
error [electron-message-handler] Conversation state not found conversationId=<redacted> rendererWindowAppearance=avatarOverlay
warning Recoverable Chromium child process gone exitCode=101457950 processType=GPU reason=crashed serviceName=GPU
warning Recoverable Chromium child process gone exitCode=18 processType=GPU reason=launch-failed serviceName=GPU

Windows AppModel logs after the crash:

0x3CFC: Cannot create the process for package <NULL> because an error was encountered while checking the machine-level package status. The application cannot be started. Try reinstalling the application to fix the problem.

Package state after the crash:

Name         PackageFullName                               Status
OpenAI.Codex OpenAI.Codex_26.721.4979.0_x64__2p2nqsd0c76g0 Modified, NeedsRemediation

Recovery / Workaround

The only reliable local workaround so far:

1. Quarantine %APPDATA%\Codex\web.
2. Reinstall the Microsoft Store package.
3. Avoid reopening the same problematic conversation.

After quarantine + reinstall, the package returns to Status: Ok and the app launches again. Reopening the same conversation reproduces the failure.

Request

Please fix the Codex Desktop conversation/browser-sidebar resume path so stale or corrupt conversation-local browser state cannot crash the app or corrupt the AppX launch state. A safe UI/CLI option to reset only one conversation's local desktop/browser-sidebar state would also make this recoverable without full reinstall.