Windows Codex desktop app fails on zero-argument launch, but starts normally with any argument

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

Codex.exe FileVersion: 149.0.7827.115

What subscription do you have?

Enterprise Edition

What platform is your computer?

OS: Windows 11 Package: OpenAI.Codex_26.611.8273.0_x64__2p2nqsd0c76g0

What issue are you seeing?

Issue

Launching Codex from the Start Menu does not open the Codex desktop app correctly. Instead, it opens the default browser home page / blank browser page. Running Codex.exe directly with no arguments also does not enter the normal Codex desktop startup path.

What steps can reproduce the bug?

& "C:\Program Files\WindowsApps\OpenAI.Codex_26.611.8273.0_x64__2p2nqsd0c76g0\app\Codex.exe"

What is the expected behavior?

Actual result

• No new Codex desktop logs are written.
• The normal Codex desktop startup sequence does not appear.
• No persistent WindowsApps Codex desktop process remains visible.
• User-visible behavior is a browser home page / blank page instead of the Codex app.

Expected result

A zero-argument launch should load the Codex desktop app and open the main Codex window.

Diagnostics

The following commands all start the Codex desktop app successfully:

Codex.exe --no-first-run
Codex.exe --enable-logging=file
Codex.exe --codex-probe-root-cause

When any argument is present, the logs show the full startup sequence:

Launching app
Starting app-server connection hostId=local transport=stdio
Transport start success
Codex CLI initialized
window main frame finished load
window ready-to-show
[startup][renderer] app routes mounted

This suggests the issue is not specific to --no-first-run. The problem appears to be the zero-argument startup path. If any argument is present, even an inert/unknown one, Codex enters the correct app bootstrap path.

Additional information

Additional observations

• AppxManifest.xml declares Executable="app/Codex.exe" with no arguments.
• The package contains both:
• app\resources\app.asar
• app\resources\default_app\
• Suspect: on zero-argument launch, the shell/runtime may fail to load resources\app.asar and either exits or falls back to the Electron/Chromium default app behavior.
• Some non-fatal errors appear during successful launches too, including Statsig brand_name=null, missing fs/readFile path, remote SSH timeout, and git dubious ownership. These do not appear to be the root cause of the startup issue.

Workaround

Create a shortcut pointing to:

C:\Program Files\WindowsApps\OpenAI.Codex_26.611.8273.0_x64__2p2nqsd0c76g0\app\Codex.exe

with this argument:

--no-first-run

This reliably bypasses the zero-argument startup issue.