Windows Store Codex enters "Modified, NeedsRemediation" after opening any webpage and becomes unlaunchable #35290

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

26.721.4979.0 (Microsoft Store)

What subscription do you have?

Free

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

After updating Codex to version 26.721.4979.0, the application consistently becomes unusable after opening any webpage inside the app.

The issue is fully reproducible.

What steps can reproduce the bug?

1. Install Codex from Microsoft Store.
2. Launch Codex normally.
3. Open any webpage inside Codex (not a specific URL; any webpage reproduces the issue).
4. Wait several seconds.
5. Codex crashes.
6. After that, Codex can no longer be launched.
7. Clicking the Codex icon only shows "Failed to open Microsoft Store."

What is the expected behavior?

Codex should continue running after opening a webpage.

Additional information

Diagnostics

PowerShell:

Get-AppxPackage OpenAI.Codex

Result:

Status : Modified, NeedsRemediation

Other observations:

• Package files still exist.
• AppxManifest.xml exists and is valid.
• PackageUserInformation reports the package as Installed.
• Reset-AppxPackage does not resolve the issue.
• Event Viewer contains no Application Error or Windows Error Reporting entries related to the crash.
• Reliability Monitor reports nothing.
• LocalState remains empty.

The issue appears every time after opening any webpage.