codex - 💡(How to fix) Fix Windows Desktop 26.527.3686.0: clicking toast notification launches Codex.exe with raw type=click&tag=... and shows Electron error

Summary

On Windows, clicking a Codex desktop notification can launch a new Codex.exe process with the raw toast activation arguments as the first app argument:

"C:\Program Files\WindowsApps\OpenAI.Codex_26.527.3686.0_x64__2p2nqsd0c76g0\app\Codex.exe" type=click&tag=10373975442458207603

That process then shows an Electron startup dialog:

Error launching app

Unable to find Electron app at C:\Program Files\WindowsApps\OpenAI.Codex_26.527.3686.0_x...\type=click&tag=10373975442458207603

Cannot find module 'C:\Program Files\WindowsApps\OpenAI.Codex_26.527.3686.0_x...\type=click&tag=10373975442458207603'

It looks like the notification activation payload is being passed to Electron as an app path instead of being handled as a Windows notification activation event / second-instance argument.

Environment

• OS: Microsoft Windows 11 Home Single Language
• OS version: 10.0.26200, build 26200, x64
• Codex package: OpenAI.Codex_26.527.3686.0_x64__2p2nqsd0c76g0
• Codex app version: 26.527.3686.0
• Install location: C:\Program Files\WindowsApps\OpenAI.Codex_26.527.3686.0_x64__2p2nqsd0c76g0

Observed behavior

1. Codex desktop is already running normally.
2. A Windows notification from Codex is clicked.
3. Windows starts another Codex.exe process via WpnUserService.
4. The new process command line is:

"C:\Program Files\WindowsApps\OpenAI.Codex_26.527.3686.0_x64__2p2nqsd0c76g0\app\Codex.exe" type=click&tag=10373975442458207603

1. The new process displays the Electron error dialog above. The existing main Codex window remains usable.

Expected behavior

Clicking a Codex notification should focus/open the relevant Codex window/thread, or no-op gracefully. It should not spawn a new Electron process that treats type=click&tag=... as an application path.

Workaround used locally

To stop the repeated popup, I disabled Windows notifications for Codex and cleared Codex notification history:

$key = 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Notifications\Settings\OpenAI.Codex_2p2nqsd0c76g0!App'
New-ItemProperty -Path $key -Name Enabled -PropertyType DWord -Value 0 -Force
[Windows.UI.Notifications.ToastNotificationManager, Windows.UI.Notifications, ContentType = WindowsRuntime] | Out-Null
[Windows.UI.Notifications.ToastNotificationManager]::History.Clear('OpenAI.Codex_2p2nqsd0c76g0!App')

This prevents the user from triggering the faulty notification launch path, but it disables Codex notifications entirely.

Additional notes

• The main app files exist (app\Codex.exe, app\resources\app.asar, and bundled resources\codex.exe).
• This appears distinct from full app launch failure: the already-running app continued working; only the notification-click spawned process failed.
• Possibly related to Windows/MSIX activation handling in the same 26.527.3686.0 release line.