Codex MS Store App crashes on launch (ACCESS_VIOLATION at 0x0) -- Version 26.601.2237.0

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

26.601.2237.0 (Microsoft Store / AppX, x64)

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Windows 10 Build 26200 (x64)

What issue are you seeing?

The Codex desktop app never launches. Clicking the icon (Start Menu or taskbar) produces no visible window, no splash screen, no error dialog. The process starts and crashes within 1-2 seconds, leaving only Crashpad minidump files.

What steps can reproduce the bug?

1. Install Codex from Microsoft Store (Product ID: 9PLM9XGG6VKS)
2. Click Codex icon in Start Menu
3. App process starts briefly, crashes silently
4. Crash dumps appear at: %LOCALAPPDATA%\Packages\OpenAI.Codex_2p2nqsd0c76g0\LocalCache\Roaming\Codex\web\Codex\Crashpad\reports\
5. No .codex directory is ever created
6. No window/splash/error message is ever shown

What is the expected behavior?

Codex should launch and display either the login screen or the main application window.

Additional information

The crash is at address 0x0000000000000000, meaning some function pointer or module reference is NULL during early initialization. This is before any user-visible code runs.

The .codex directory never gets created, confirming the crash happens before user data initialization.

This is not the codex://new deep-link protocol bug (#25297), because the crash occurs even when launching Codex.exe directly with no protocol arguments.

The app uses owl runtime (OpenAI's Electron shell), identified from resources/owl-electron-app.json: {"runtimeName":"owl","packagedFrom":"D:\\a\\openai\\openai\\codex\\codex-apps\\electron\\out\\Codex-win32-x64"}.

The AppxManifest specifies MaxVersionTested="10.0.26100.0" while the host system is running build 10.0.26200.0 (Windows Insider Dev Channel).

Codex CLI (@openai/codex v0.136.0, installed via npm) works fine on the same machine, confirming the issue is specific to the desktop app's Electron/AppX packaging, not a system-wide incompatibility.