26.527.3686.0 introduces invisible/transparent UI composition bug

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

26.519.81530.0

What subscription do you have?

Pro

What platform is your computer?

Microsoft Windows NT 10.0.21996.0 x64

What issue are you seeing?

Summary

This issue concerns the Windows Codex Desktop Application MSIX package.

A recent Windows Codex update appears to have introduced a graphics/composition rendering regression affecting Windows 11. The application launches and remains active, but the main Codex UI fails to render correctly on the desktop.

The app is visible from the taskbar preview when hovering over the active Codex icon, and the background processes appear to be running. However, on the actual desktop, only a grey sidebar/scrollbar or partial transparent surface is visible. The UI appears to still be clickable/interactable, but the rendered surface is invisible or not properly painted by the Windows desktop compositor.

In my case, the issue first occurred while Codex was running and a video game was also active. After the game exited and Windows appeared to reset/recover the graphics driver/compositor state, Codex became invisible. After that point, the issue persisted in affected Codex versions.

Only the input prompt could sometimes be made visible by double-clicking the notification tray icon.

Manual MSIX rollback/testing via PowerShell confirms this is a regression introduced in later builds.

Edit: 10.06.26 - This appears to be a targeted specific bug, only unique to Microsoft Windows NT 10.0.21996.0 x64.

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Regression confirmed

Tested via manual MSIX installation using PowerShell:

| Codex Version | Result |
| ---------------------------------------------------------------- | ------------------------------------------------------------ |
| 26.519.5221.0 | Works correctly |
| 26.519.11010.0 package / About dialog reports 26.519.81530.0 | Works correctly |
| 26.527.3686.0 | Broken — introduces invisible/transparent UI composition bug |
| 26.601.2237.0 | Broken — issue remains present |

This strongly suggests the regression was introduced between the 26.519.x branch and 26.527.3686.0.

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Working version test: 26.519.5221.0

I rolled back the application to 26.519.5221.0, the May 23rd release, using manual MSIX installation.

Result: the application GUI rendered successfully through the Windows 11 desktop compositor. The bug does not exist in this version.

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Working version test: 26.519.11010.0 / About reports 26.519.81530.0

I then removed that version and installed 26.519.11010.0 via manual MSIX installation.

Although the package version appears to be 26.519.11010.0, the Codex About dialog reports the application version as 26.519.81530.0.

Result: the bug does not exist. The application launches successfully and the GUI renders correctly.

<img width="1046" height="523" alt="Image" src="https://github.com/user-attachments/assets/b7c94501-03a9-4535-824f-ca9755d4c6a5" />

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Broken version test: 26.527.3686.0

Next, I removed the package and installed 26.527.3686.0 via MSIX using PowerShell.

<img width="1226" height="957" alt="Image" src="https://github.com/user-attachments/assets/c7975db4-afbf-4b10-abad-a38418b640b0" />

After installing this version and later versions, the graphics/composition bug appears. The user cannot use the application normally because the Codex window becomes invisible, transparent, or visually unpainted.

<img width="1267" height="945" alt="Image" src="https://github.com/user-attachments/assets/48a73fea-7028-45eb-8d1b-e6e9a64aad4a" />

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What steps can reproduce the bug?

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Steps to reproduce

1. Install Codex Desktop for Windows version 26.519.x.
2. Launch Codex.
3. Confirm the UI renders normally.
4. Uninstall Codex.
5. Install or update to Codex Desktop version 26.527.3686.0.
6. Launch Codex.
7. Observe that the app window becomes transparent, invisible, or visually unpainted, while the UI remains clickable/interactable.
8. Roll back to 26.519.x.
9. Observe that the UI immediately renders correctly again.

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What is the expected behavior?

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Expected behavior

Codex should render normally on Windows 11, with the full application UI visible and usable.

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Additional information

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Actual behavior

Starting with 26.527.3686.0, the Codex window suffers from a Windows composition/rendering failure.

The app appears to launch, and the UI remains clickable/interactable, but the visual surface is transparent, invisible, or not painted correctly on the desktop.

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System information

• OS: Windows 11
• GPU: NVIDIA GeForce GTX 1060 6GB
• RAM: 32GB
• Platform: Intel Skylake / H170 platform
• Issue survives NVIDIA driver reinstall
• Issue survives GPU cache clearing
• Rolling back to 26.519.x immediately resolves the issue

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Workaround

The current workaround is to manually uninstall the affected Codex version and roll back to the last known working 26.519.x MSIX package.

Example PowerShell rollback:

Get-AppxPackage -Name "OpenAI.Codex" -AllUsers |
    ForEach-Object {
        Remove-AppxPackage -Package $_.PackageFullName -AllUsers
    }

Add-AppxPackage -Path "PATH\TO\WORKING\26.519.x\codex.msix"

After reinstalling a working 26.519.x version, Codex renders normally again.

Users should avoid updating to 26.527.3686.0 or later until the Windows composition/rendering regression is fixed.

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Notes

This does not appear to be a general Windows installation issue, because older Codex 26.519.x versions render correctly on the same system.

The issue appears specific to newer Codex Windows builds, likely involving one of the following areas:

• Windows desktop compositor
• DirectComposition
• GPU compositing
• WebView / Chromium rendering layer
• WinUI / Windows App SDK rendering path
• Transparent/acrylic window handling

The confirmed first bad build in my manual testing is:

26.527.3686.0

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