[Windows][26.820.9563.0] ChatGPT Desktop launches headless after upgrade from Classic; no renderer/window created

What version of the Codex / ChatGPT Desktop app are you using?

26.820.9563.0

Package:

OpenAI.Codex_26.820.9563.0_x64__2p2nqsd0c76g0

App ID:

OpenAI.Codex_2p2nqsd0c76g0!App

Executable:

app\ChatGPT.exe

Platform

Windows x64.

What issue are you seeing?

After upgrading from ChatGPT Classic to the new unified ChatGPT Desktop application, the application launches processes in the background but never creates a visible window.

ChatGPT Classic works correctly on the same machine. After upgrading to OpenAI.Codex 26.820.9563.0, multiple ChatGPT.exe processes start and remain responsive, but every process has:

MainWindowHandle = 0
MainWindowTitle  = <empty>

The main process consumes substantial RAM/CPU and child processes are created, but the UI never appears.

This is related to #41059, but differs in one important way: no “Unable to locate the Codex CLI binary” dialog was observed in this reproduction. The app becomes headless directly after upgrading from ChatGPT Classic.

Process behavior observed

The main process starts normally:

ChatGPT.exe

It successfully creates:

• Crashpad handler
• GPU process
• Network utility process

Examples:

ChatGPT.exe --type=crashpad-handler
ChatGPT.exe --type=gpu-process
ChatGPT.exe --type=utility --utility-sub-type=network.mojom.NetworkService

However, no process with:

ChatGPT.exe --type=renderer

is ever created.

The primary ChatGPT.exe process was observed using roughly 480–540 MB RAM with ~52 threads and active CPU usage, while still having MainWindowHandle = 0.

This suggests initialization progresses significantly but stops before Chromium renderer/window creation.

Windows activation diagnostics

Windows reports successful package registration and activation.

Microsoft-Windows-AppModel-Runtime/Admin shows:

• Event ID 201: process created successfully for OpenAI.Codex_2p2nqsd0c76g0!App
• Event ID 210: Desktop AppX container created successfully
• Event ID 211: process added to Desktop AppX container successfully

Microsoft-Windows-TWinUI/Operational shows:

• Event ID 1621
• activation result: 0
• message indicates the operation completed successfully

Microsoft-Windows-AppXDeploymentServer/Operational confirms staging and registration of:

OpenAI.Codex_26.820.9563.0_x64__2p2nqsd0c76g0

completed successfully.

The package manifest reports:

Executable : app/ChatGPT.exe
EntryPoint : Windows.FullTrustApplication

Capabilities include:

appLicensing
runFullTrust
unvirtualizedResources
internetClient

Therefore, the failure appears to occur after Windows successfully transfers control to ChatGPT.exe.

User-data behavior

The Chromium crashpad process is launched with:

--user-data-dir=C:\Users\<USER>\AppData\Roaming\Codex\web\Codex

That directory was not created automatically.

To test whether this was a filesystem/permission issue, the directory was created manually. The user has full control permissions on %APPDATA%\Codex, but ChatGPT still did not populate the directory or create a UI.

The packaged app container under:

%LOCALAPPDATA%\Packages\OpenAI.Codex_2p2nqsd0c76g0

is created successfully with standard directories (LocalCache, LocalState, RoamingState, Settings, TempState, etc.), but no meaningful application state/log/database files appeared there during the failed launch.

Troubleshooting already performed

The following did not resolve the problem:

1. Repair the application from Windows Settings.
2. Reset the application.
3. Completely uninstall OpenAI.Codex.
4. Verify Get-AppxPackage OpenAI.Codex returns nothing after removal.
5. Reinstall ChatGPT Classic from Microsoft Store.
6. Confirm ChatGPT Classic opens correctly.
7. Upgrade again to the new unified ChatGPT Desktop app.
8. Launch using:

   shell:AppsFolder\OpenAI.Codex_2p2nqsd0c76g0!App
   

9. Launch ChatGPT.exe directly.
10. Launch with --disable-gpu.
11. Launch with --disable-gpu --disable-features=Vulkan.
12. Verify AppX registration / activation logs.
13. Verify filesystem permissions for %APPDATA%\Codex.
14. Manually create the expected Chromium user-data directory.

None of these changed the behavior.

Steps to reproduce

1. Install ChatGPT Classic on Windows.
2. Confirm ChatGPT Classic opens normally.
3. Upgrade to the new unified ChatGPT Desktop app (OpenAI.Codex 26.820.9563.0).
4. Launch ChatGPT.
5. Observe multiple ChatGPT.exe processes running in Task Manager / PowerShell.
6. No visible UI appears.
7. Check processes:

   Get-Process ChatGPT | Select Id,MainWindowTitle,MainWindowHandle,Responding,Path
   

8. All processes show MainWindowHandle = 0.
9. Inspect process command lines and observe crashpad/GPU/network utility children but no --type=renderer process.

Expected behavior

The ChatGPT Desktop window should be created and displayed after launch.

A Chromium renderer process should start as part of normal UI initialization.

Actual behavior

The application remains running headlessly with no visible UI.

The main process remains responsive and uses CPU/RAM, but no renderer/window is created.

Impact

This is a blocking issue for the new unified ChatGPT Desktop application.

ChatGPT Classic remains usable, but it does not provide the newer unified ChatGPT / Work / Codex desktop experience.

Additional observations

The evidence suggests the failure is inside the application runtime between Chromium initialization and renderer/window creation, rather than AppX registration, package activation, GPU initialization, or basic filesystem permissions.

Related issue: #41059

Start by reproducing the upgrade path on Windows and launching app\ChatGPT.exe through the reported AppX entry point. Inspect the startup path around Chromium renderer creation using the supplied PowerShell process checks, and compare it with a working Classic installation. Done means the unified app creates a visible window and a renderer process after launch.