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Codex Issues / #25754

Codex App: sidebar and top menu become transparent when maximized on Windows

Resolved 💬 3 comments Opened Jun 2, 2026 by yufanwu345-eng Closed Aug 6, 2026
💡 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

What subscription do you have?

Unknown / not visible from the app UI.

What platform is your computer?

Microsoft Windows NT 10.0.19045.0 x64

GPU / display details observed locally:

  • NVIDIA GeForce RTX 3060 Laptop GPU, driver 32.0.15.9649, driver date 2026-05-05
  • GameViewer Virtual Display Adapter, driver 15.6.5.199
  • Windows transparency effects were tested both on and off. The issue still reproduces with EnableTransparency = 0.

What issue are you seeing?

When the Codex Windows desktop app is maximized, the left sidebar and the top title/menu area become transparent and show the Windows desktop behind them. This affects the project/conversation sidebar on the left and the menu/title area at the top.

The same UI renders normally when the app is not maximized. The issue returns as soon as the window is maximized again.

What steps can reproduce the bug?

  1. Open the Codex Windows desktop app.
  2. Keep the window non-maximized. The sidebar and top area render normally.
  3. Click the maximize button.
  4. Observe that the left sidebar and top title/menu area become transparent, exposing desktop icons and wallpaper behind the app.
  5. Restore the window to a non-maximized size. The UI returns to normal.

I already tried the following workarounds and the issue still reproduces:

  • Restarted the Codex app.
  • Disabled Windows transparency effects.
  • Reset the Windows GPU rendering stack with Win + Ctrl + Shift + B.
  • Cleared Codex rendering/cache folders under %APPDATA%\Codex, including GPUCache, DawnGraphiteCache, DawnWebGPUCache, Code Cache, and Cache.

What is the expected behavior?

When the Codex app is maximized, the left sidebar and top title/menu area should keep their normal opaque background and should not show the Windows desktop through the app window.

Additional information

This appears to be specific to the maximized window state. Manually resizing the app close to full screen without using maximize appears to avoid the rendering issue.

View original on GitHub ↗

3 Comments

github-actions[bot] contributor · 2 months ago

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

  • #25513
  • #25347
  • #25217
  • #25417
  • #25235

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leung-2023 · 2 months ago

I can reproduce the same issue on another Windows 10 x64 machine.

Environment:

  • Codex About dialog version: 26.527.60818
  • Microsoft Store package path observed: OpenAI.Codex_26.527.7698.0_x64__2p2nqsd0c76g0
  • OS: Microsoft Windows 10 Pro 22H2, build 19045
  • Architecture: AMD64 / x64
  • CPU identifier: Intel64 Family 6 Model 158 Stepping 10, GenuineIntel
  • GPU: Intel(R) UHD Graphics 630, driver 31.0.101.2140
  • Virtual display driver present: OrayIddDriver Device, driver 17.50.19.949
  • Display logical size observed locally: 1536 x 864
  • Windows transparency effects tested disabled: EnableTransparency = 0

Behavior:

  • Codex renders normally when not maximized.
  • When maximized, the left sidebar and top/title/menu area become transparent and show the desktop or another window behind the app.
  • Restoring the window immediately makes the sidebar render normally again.

Troubleshooting already tried:

  • Confirmed Codex is already up to date.
  • Uninstalled and reinstalled Codex.
  • Disabled Windows transparency effects.
  • Cleared/renamed most Codex Chromium/GPU rendering caches under %APPDATA%\Codex, including GPUCache, DawnGraphiteCache, DawnWebGPUCache, Code Cache, and Cache.
  • Restarted Codex after cache cleanup.

Result:
The issue still reproduces after all of the above. It appears specific to the native maximized window state.

ivantrubnev · 2 months ago

I can reproduce the same issue.

Environment:

  • Windows 10 Pro 22H2, build 19045
  • Codex App: 26.527.7698.0
  • Package: OpenAI.Codex_26.527.7698.0_x64__2p2nqsd0c76g0
  • GPU: NVIDIA GeForce RTX 4060 Ti, driver 32.0.16.1047
  • Also present with Intel UHD Graphics 770 available
  • DPI: 100%, AppliedDPI 96
  • Multiple monitors, 4 physical displays

Symptoms:

  • Only happens when the Codex app window is maximized.
  • Left sidebar, top/title/menu area, and some bottom/status areas become transparent and show the Windows desktop behind the app.
  • Restored window manually resized almost fullscreen renders normally.
  • Text selection/caret hit testing in the composer appears offset: the real cursor position is left of the displayed text.

Tried and did not help:

  • Restarting Codex and rebooting Windows
  • Disabling Windows transparency effects
  • Updating GPU drivers
  • Resetting Codex web profile/cache
  • Launching with Chromium/GPU workaround flags, including disabling DirectComposition / GPU compositing / GPU
  • Removing phantom display and restoring monitor layout

Workaround:

  • Restore the window and manually resize it almost fullscreen without using maximize.