Codex desktop app intermittently freezes Windows shell/UI; opening Codex Settings stops the freeze

[WilliamSoapHealth]

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

26.325.3894.0

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Windows 11 Pro 25H2, OS Build 26200.8037, x64

What issue are you seeing?

While using the Codex desktop app on Windows 11, Windows shell/UI components intermittently freeze.

Observed symptoms:

• Start menu stops responding
• Taskbar becomes unusable
• Desktop/shell interaction degrades
• Alt+Tab stops working
• If I try to launch another program as Administrator, the Windows UAC confirmation dialog may fail to appear until later
• Chrome and Task Manager can continue working while the shell/UI is partially frozen

Important behavior:

• Closing Codex restores normal behavior
• Also, the freeze stops if I open the Codex Settings screen
• This suggests the issue may depend on a specific Codex app view/state, not just the app being open

The issue does not always show up as a full crash. In multiple reproductions, the shell/UI becomes temporarily frozen without a formal new Application Hang event for Explorer/StartMenuExperienceHost, even though the user-visible shell is clearly impaired.

What steps can reproduce the bug?

1. Open the Codex desktop app on Windows 11.
2. Use the app normally for some time.
3. Try to open the Start menu.
4. Intermittently, the shell/UI enters a frozen state:
   • Start menu becomes unresponsive
   • Taskbar becomes unresponsive
   • Alt+Tab may stop working
   • UAC prompt may not appear if another app is started as Administrator
5. While the freeze is happening, open the Codex Settings view or just close the Codex app.
6. In my testing, switching to Settings can stop the freeze.

Additional validation:

• Microsoft PowerToys was uninstalled
• The machine was rebooted
• The issue still reproduced afterward

What is the expected behavior?

Codex should remain usable without affecting Windows shell/UI components such as the Start menu, taskbar, Alt+Tab behavior, desktop interaction, or UAC prompt display.

Additional information

I captured multiple live reproductions with a background monitor that sampled relevant shell/Codex/WebView2 processes once per second and also tracked Event Viewer entries and WER reports.

Key findings:

1. Earlier live repro:

• 19:23:50 -> Codex.exe hung (Application Hang, MoAppHang)
• 19:23:52 -> WER archived the Codex hang report
• 19:24:30 -> explorer.exe was still running but captured as responding=false by the monitor

This suggests the Codex hang preceded and likely contributed to the shell becoming unresponsive.

2. Marked freeze window:

• 19:48:38 -> freeze-start
• 19:48:53 -> freeze-end

During that window:

• no new formal Application Hang event was emitted for Explorer/StartMenuExperienceHost
• shell processes remained alive and reported as responsive
• however, shell CPU usage was elevated:
  • explorer.exe: about 52-54 CPU
  • StartMenuExperienceHost.exe: about 26-27 CPU
  • SearchHost.exe: about 11-12 CPU
• at the same time, Codex processes showed high CPU/memory pressure and abrupt memory churn

3. Marked freeze window where opening Settings stopped it:

• 20:00:29 -> freeze started when I tried to open the Start menu
• 20:00:40 -> opening Codex Settings stopped the freeze

During that window:

• no new formal Application Hang event was emitted
• shell processes remained alive and reported as responsive
• shell CPU usage was elevated:
  • explorer.exe: about 64-66 CPU
  • StartMenuExperienceHost.exe: about 30-32 CPU
  • SearchHost.exe: about 13-15 CPU
• multiple Codex processes were simultaneously under significant load:
  • one Codex process sustained about 45-51 CPU and roughly 430-534 MB working set
  • another sustained about 35-45 CPU
  • another showed about 15-17 CPU with large private memory usage

Additional relevant observations:

• msedgewebview2.exe also showed large memory changes during some repro windows
• DISM /Online /Cleanup-Image /RestoreHealth completed successfully
• sfc /scannow found and repaired corrupted files
• even after that, the issue still reproduced

Current interpretation:

• this appears to be an intermittent Windows shell/UI freeze associated with Codex activity
• the issue may be tied to a specific Codex UI state/view, because opening Settings appears to stop the freeze
• the problem does not always manifest as a formal shell crash event

[github-actions]

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

• After running the Codex APP in Win11 for a long time, the client freezes severely, causing the whole machine to freeze severely #15481

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[zunzster]

I get this exact taskbar and explorer freeze too.
I note this was on a repo where I not pushed a github commit yet,
Looking in RAMMAP, I can see 100s of git.exe and conhost.exe which don't show in Task Manager processes list.

[Karaik]

Same here. But opening Codex Settings does not stop the freeze for me.
The only thing that helps is closing the Codex GUI.

[paulaccredo]

Yeah, opening Settings didn't help me either. Codex seems to be rapidly creating 100s of zombie processes (git.exe and conhost.exe) which use up page table memory and don't get cleaned up and eventually prevent other processes from launching.

[CognitiveCodeAI]

I’m having seen issue. I’m forced to reboot my computer. The fix I found is to uninstall Codex and just use Claude code.

[zunzster]

I believe I've tracked this down to a bug in AMD Adrenaline Edition drivers that caused a zombie process handle leak as I have a AMD Ryzen 7 series CPU. More details here https://yngve.vivaldi.net/amd-you-infected-my-pc-with-zombies/
So, the actual bug is in the AMD drivers, but given that Codex spawns a LOT of short-lived background git processes, that magnifies the problem.

Do the other people reporting this have AMD GPUs or CPUs?

[AIAllTheThingz]

Nvidia drivers for me