Codex Windows desktop app crashes on startup: app-server websocket closed code=3221225781
Resolved 💬 4 comments Opened May 20, 2026 by deeisom Closed May 20, 2026
💡 Likely answer: A maintainer (github-actions[bot], contributor)
responded on this thread — see the highlighted reply below.
Codex Windows desktop app crashes immediately after opening.
Error shown:
(code=3221225781, signal=null)
Most recent error: Codex app-server websocket closed (code=3221225781)
What happens:
- I install/open Codex on Windows.
- The app checks for updates and says the latest version is installed.
- Immediately after that, this error screen appears.
- Reload does not fix it.
- Check for updates does not fix it.
- Open Config.toml does nothing.
- I manually checked C:\Users\DeAnno\.codex.
- There was no config.toml originally.
- I tried creating config.toml with Windows sandbox settings, but the same error happened.
- I also tried Repair/Reset from Installed Apps, but the crash still happens.
- There is no sandbox.log file, so it may be crashing before sandbox startup.
Environment:
- Windows 11 Pro
- Codex installed from Microsoft Store
- Using Codex desktop app, not VS Code
<img width="1202" height="747" alt="Image" src="https://github.com/user-attachments/assets/cc1a7a99-4725-4692-a8e1-02d8dc1627a8" />
4 Comments
Potential duplicates detected. Please review them and close your issue if it is a duplicate.
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I reviewed the potential duplicates flagged by the bot.
https://github.com/openai/codex/issues/22865 has the same error code (3221225781), but it is closed as not planned and does not appear to include a resolution or detailed troubleshooting.
https://github.com/openai/codex/issues/23672 appears related, but it uses a different error code (3221225501), while my error is 3221225781.
I am leaving this issue open because I still do not have a workaround or fix for the Windows Codex desktop app crash.
Small correction to my original post: the folder I checked was:
C:\Users\DeAnno.codex
Please let me know if this should be merged into a specific issue, or if there are logs/settings I should provide.
just install latest vc++ runtime and reboot
Thanks! Worked perfectly.