[Windows 10][26.915.4065.0] Run as administrator fails with package-not-found popup

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

26.915.4065.0 (installed Store package; About dialog not independently checked)

What subscription do you have?

Unknown / not provided; failure occurs during Windows app launch

What platform is your computer?

Microsoft Windows NT 10.0.19045.0 x64 (Windows 10 Home)

What issue are you seeing?

The ChatGPT/Codex desktop app launches normally at medium integrity, but an attempt to launch it with Administrator privileges fails. Windows shows a popup with an error sound; the user describes its message as saying the package cannot be found. This prevents use of existing desktop app chats, projects, and ongoing tasks with Administrator privileges.

Diagnostics on the affected PC:

• Installed Store package: OpenAI.Codex_26.915.4065.0_x64__2p2nqsd0c76g0; Get-AppxPackage reports Status: Ok.
• app\ChatGPT.exe exists and normal app launch works. Get-StartApps lists OpenAI.Codex_2p2nqsd0c76g0!App.
• The manifest targets Windows.Desktop MinVersion=10.0.19041.0; the PC is build 19045.
• The manifest declares runFullTrust but does not declare allowElevation. This is a possible packaging clue, not a confirmed cause.
• AppModel-Runtime/Admin event ID 204, 2026-09-19 08:48 local time: 0x800704C7: Cannot create the process for package OpenAI.Codex_26.915.4065.0_x64__2p2nqsd0c76g0 because an error was encountered while elevating the token. [LaunchProcess]
• UAC is enabled (EnableLUA=1).

What steps can reproduce the bug?

1. On Windows 10 build 19045 x64, install/open Store package OpenAI.Codex 26.915.4065.0.
2. Confirm normal launch works.
3. Attempt to start the desktop app using Run as administrator.
4. Observe the package-not-found popup and no elevated app session.

The exact launch entry point (Start menu, shortcut, or direct executable) has not yet been confirmed. The failure occurs before a Codex task starts, so there is no session ID or context-window metric for this attempt.

What is the expected behavior?

The desktop app launches elevated, and the Codex agent inherits that permission level, as the official Windows instructions describe.

Additional information

Official instructions: https://learn.chatgpt.com/docs/windows/windows-app

Related #28107 and #25296 concern the app launching but the agent/tool host ending up at medium integrity. In this report, the elevated desktop app launch itself fails.

Please verify whether this Store package is intended to support elevation on Windows 10 and whether the missing allowElevation capability or app activation path explains the failure. No repair, reinstall, manifest modification, or UAC policy change was performed during this investigation.

Start by reproducing the launch path on Windows 10 build 19045 with package 26.915.4065.0 and capture the package activation behavior around AppModel-Runtime/Admin event 204. Inspect the Store manifest and compare its runFullTrust and allowElevation declarations with the documented elevated-launch expectation. Done means the intended launch path starts the desktop app elevated without the package-not-found failure.