Windows setup cannot complete (UAC never appears)

Additional investigation:

I collected some diagnostics while troubleshooting.

Environment:

• Windows 11 Pro
• ChatGPT Desktop 26.707.9564.0
• Local administrator account

Already tested:

• Reinstalled from Microsoft Store
• Reinstalled from the official installer
• UAC set to the highest level
• Rebooted multiple times
• Removed Kaspersky completely
• Ran ChatGPT as Administrator

Results:

• No UAC prompt is ever shown.
• ChatGPT.exe starts normally.
• codex.exe starts normally.
• Windows Event Viewer contains no AppX deployment or UAC errors.

I also found that the application installs:

%LOCALAPPDATA%\OpenAI\Codex\bin\<version>\codex-windows-sandbox-setup.exe

Running it manually returns:

Error: helper_request_args_failed: expected payload argument

which suggests the helper itself exists and expects to be launched by ChatGPT with an internal payload.

Desktop logs are attached.

The logs also consistently contain:

Failed to load desktop settings from config.toml
Invalid TOML document

The config.toml appears to contain only null bytes.

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

• #32492
• #32149
• #32248
• #32808
• #32255

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thks

I've discovered another critical root cause for the "Finish Windows setup" hang (where the UAC prompt never triggers) that is related to authentication rather than Windows privileges or system features.

The Underlying Issue

If your user session has expired or the OAuth refresh token has been revoked, the desktop app fails to fetch the cloud configuration bundle (cloudConfigBundle) during startup:

failed to load configuration: Your access token could not be refreshed because your refresh token was revoked. Please log out and sign in again.

This causes the backend windowsSandbox/setupStart call to fail with a 401 Unauthorized / Auth error. Instead of displaying a prompt to log out and log in again, the Desktop UI incorrectly routes this error to the "Finish Windows setup" gate, making it appear as a permissions/sandbox setup failure.

The Fix / Workaround

To break the loop and force the app to show the login screen:

1. Close the ChatGPT/Codex Desktop application completely.
2. Open File Explorer and navigate to your user profile directory: %USERPROFILE%\.codex (usually C:\Users\<username>\.codex).
3. Locate the file named auth.json.
4. Rename auth.json to auth.json.bak (or delete it).
5. Relaunch the ChatGPT/Codex app.

The app will now detect that no login session exists, skip the sandboxing gate, and successfully route you to the Sign In screen. Once you log back in, a fresh OAuth session will be established, and the app will open normally.

The app will now detect that no login session exists, skip the sandboxing gate, and successfully route you to the Sign In screen. Once you log back in, a fresh OAuth session will be established, and the app will open normally.

Tried it, I het a new auth session, and after the config it ;amds on teh last step UAC and fails the same way.

<img width="1152" height="1044" alt="Image" src="https://github.com/user-attachments/assets/8f153458-3d09-4a4a-aeff-6d28a3904d15" />

THe solution to delete config.toml worke for me (https://github.com/openai/codex/issues/32492) - the file was corrupted.
How do I recover my previous sessions now? My new ChatGPT desktop app is empty. Did I lost all my work in progress?

Confirmed, this resolved the issue for me.

The root cause was a corrupted config.toml.

Renaming:

config.toml
→
config.toml.bak

forced the app to recreate the configuration on startup. After that, the "Finish Windows setup" screen disappeared and the application started normally.

In my logs, every launch contained:

Failed to load desktop settings from config.toml
Invalid TOML document

The file appears to have become corrupted (filled with null bytes), so the desktop app was unable to parse it and incorrectly ended up on the "Finish Windows setup" flow.

Thanks for pointing me to issue #32492.