Codex App on Windows reports: "Codex failed to start."
Open 💬 2 comments Opened Jun 2, 2026 by gabrielgrant
💡 Likely answer: A maintainer (github-actions[bot], contributor)
responded on this thread — see the highlighted reply below.
What version of the Codex App are you using (From “About Codex” dialog)?
26.527.7698.0 (codex won't open, so this is from the MS store's "Installed version" field)
What subscription do you have?
Plus
What platform is your computer?
Microsoft Windows NT 10.0.26200.0 x64
What issue are you seeing?
When trying to launch the Codex App, it puts an icon in the system tray, but no Window appears. Clicking the system tray icon does nothing. At some point (10+ minutes later) the following error message pops up:
<img width="464" height="160" alt="Image" src="https://github.com/user-attachments/assets/c0619759-b057-416c-bd83-529796ca8b55" />
As text for searchability:
Codex failed to start.
(code=4294967295, signal=null).
Most recent error: Codex app-server websocket closed (code=4294967295)What steps can reproduce the bug?
Launch the app
What is the expected behavior?
The app opens
Additional information
This is a fresh install from the windows store. I had codex installed previously, removed it by uninstall, and installed fresh to test.
2 Comments
Potential duplicates detected. Please review them and close your issue if it is a duplicate.
Powered by Codex Action
While all similar, none seem quite the same as the issue I'm experiencing
#25600 , #25607 seems to be different because the user is able to log in, while I'm not able to get that far
#25575 sounds similar, but the user doesn't report an error message appearing
#25671 reports a different error message