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Codex Windows app (Microsoft Store) crashes on first screen with: code=3221225477, signal=null #17485

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Description

@enjoycod1ng

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

Latest from Microsoft Store

What subscription do you have?

Pro

What platform is your computer?

Windows 10 Pro, x64 Version 2009 OS Build 26200

What issue are you seeing?

The Codex Windows app from the Microsoft Store crashes immediately on the first screen before the UI becomes usable.

Full error shown by the app:

An error has occurred
Codex crashed with the following error:

(code=3221225477, signal=null).
Most recent error: None

Some things to try:

Check your config.toml for invalid settings
Check your settings to disable running in WSL if you are seeing compatibility issues
Try downloading a different version of the extension
Click reload to restart the Codex extension, or visit our documentation for additional help.

This happens before I can use the app normally, so there is no session ID, token usage, or context window info available.

What steps can reproduce the bug?

  1. Install Codex from the Microsoft Store on Windows 10 Pro.
  2. Launch the Codex desktop app.
  3. The app crashes on the first screen before the main UI becomes usable.
  4. The same crash happens every time.

Things I already tried:

  • Used config.toml with:
    [windows]
    sandbox = "elevated"

  • Changed it to:
    [windows]
    sandbox = "unelevated"

  • Renamed config.toml to config.toml.bak so the app starts with no config file.

  • Confirmed CODEX_HOME is not set.

  • Checked Microsoft Store / winget and there is no newer version available.

Result:
The crash is the same in all cases:
(code=3221225477, signal=null)

No session ID is available because the app crashes before a usable session starts.

What is the expected behavior?

The Codex Windows desktop app should launch normally and open to the main UI instead of crashing on the first screen.

Additional information

No response

Activity

  1. added
    appIssues related to the Codex desktop app
    on Apr 11, 2026
  2. added
    bugSomething isn't working
    windows-osIssues related to Codex on Windows systems
    on Apr 11, 2026
  3. Unshanken commented on May 11, 2026

    @Unshanken

    Did you fix it? I have encountered the exact same problem today.

  4. Wangnov commented on May 22, 2026

    @Wangnov

    If you want to rule out an outdated/broken Microsoft Store package by manually trying the latest official MSIX, this unofficial mirror may help:

    https://github.com/Wangnov/codex-app-mirror

    Latest Windows MSIX:
    https://codexapp.agentsmirror.com/latest/win

    It mirrors the official Codex MSIX resolved from Microsoft Store ProductId 9PLM9XGG6VKS and includes checksums/release metadata. This is not an official OpenAI installer and may not address this specific crash, but it can help when the Store path itself is unreliable.

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