Windows desktop app's sidebar icons vanish, conversations empty, and login button does nothing after logout (browser works fine)

Summary

The Windows ChatGPT Desktop app became unusable after a rendering failure and now cannot be logged into after reinstalling.

Environment

• ChatGPT Desktop: 1.2026.133.0

• Windows 11 Enterprise 25H2

• OS Build: 26200.8655

• Microsoft Edge reinstalled

• Web version works correctly

• ChatGPT Plus account

Initial issue

1. Started a new conversation.

2. Sent a prompt.

3. The conversation was created successfully.

4. The conversation received an automatic title.

5. The assistant response never appeared.

6. The conversation remained empty except for the title.

After troubleshooting

I performed:

• Repair

• Reset

• Complete reinstall

• Reinstalled Microsoft Edge

• Rebooted Windows

After reinstalling, the application opened normally but the Log in and Sign up buttons stopped working completely.

Current behaviour

• The application starts.

• UI loads normally.

• Menus and other controls work.

• Only Log in and Sign up do nothing when clicked.

• The browser version at https://chatgpt.com works normally with the same account.

Windows Event Viewer

Application Hang:

• Event ID: 1002

• HangType: Quiesce

• Process: ChatGPT.exe

• Version: 1.2026.133.0

The application does not crash but becomes unresponsive during the authentication flow.

Additional information

I also verified:

• HTTPS URL handling works.

• Default browser works.

• OAuth page can be opened manually.

• WebView2 Runtime reports itself as already installed.

• Edge Update reports: Installation failed. The Microsoft Edge WebView2 Runtime is already installed for the system.

• Reinstalling Edge did not resolve the problem.

Expected behaviour

• Responses should render normally.

• After reinstall, the Login button should start the authentication flow.

Actual behaviour

• Responses stopped rendering.

• After reinstall, Login and Sign up no longer perform any action.