[Windows] Store app self-uninstalls (~60s after launch) - package removed in user context, disappears from Installed Apps

Start by reproducing the install-to-removal cycle and reviewing Microsoft-Windows-AppXDeploymentServer/Operational alongside the app log at %LOCALAPPDATA%\OpenAI\Codex\chrome-native-hosts-v2.json. Capture the calling process with Process Monitor, compare the 26.721.4979.0 regression with earlier builds, and identify why the user-context Remove occurs. Done means the Store app remains installed after launch and the behavior is verified on Windows 11.

Summary

On Windows 11, the Microsoft Store Codex app installs fine, launches (window shows ~1s), then is uninstalled from my account ~60 seconds later. It vanishes from Settings → Installed apps and the Store button flips back to "Install". Reinstalling loops the same behavior.

This is not a crash: there are no Windows Error Reporting (WER) or AppModel-Runtime fault events. The AppX deployment log shows a clean Remove operation running under my user SID (not SYSTEM) — i.e. the package is being deliberately deprovisioned per-user, not exiting/crashing. It's a regression: the same MSIX GUI ran fine on this machine for ~6 weeks (per the app's own native-host log) until build 26.721.x.

Environment

• OS: Windows 11 Home 25H2, build 26200.8894, x64 (AMD64)
• Store app: OpenAI.Codex_26.721.4979.0_x64__2p2nqsd0c76g0 (Store ID 9PLM9XGG6VKS)
• Codex CLI (still works): codex-cli 0.146.0-alpha.3.1
• Dependencies all present/OK: WindowsAppRuntime 1.1/1.6/1.8/2.x, VCLibs 140, .NET Native, UI.Xaml 2.7/2.8

Steps to reproduce

1. Install Codex from the Microsoft Store (completes without error).
2. Click Open. Window appears for ~1 second.
3. Window closes. ~60s later the package is gone from Installed apps; Store shows Install again.
4. Repeats every cycle.

Evidence

1. Not a crash. Application log WER (Event IDs 1000/1001/1002) and Microsoft-Windows-AppModel-Runtime/Admin contain zero Codex events.

2. Package removed by a user-context uninstall, tied to launch. From Microsoft-Windows-AppXDeploymentServer/Operational:

Register … finished successfully                                 (install completes)
Started deployment Remove operation … user SID S-1-5-21-…-1001   (~60s after launch)
Remove … finished successfully

Stage runs as SYSTEM (S-1-5-18), but Remove runs as the logged-in user — a per-user uninstall, not a Windows/servicing action. Windows does not auto-uninstall a package for crashing.

3. Only benign deployment errors (neither removes a package): 0x80073CF2 (StageUserData on an already-installed package) and 0x80070015 ("pre-launch service not ready").

4. Regression. The app's own %LOCALAPPDATA%\OpenAI\Codex\chrome-native-hosts-v2.json shows the GUI launching successfully across ~15 builds (26.608 → 26.715) from mid-June through 24 Jul 2026; the self-uninstall loop appears with 26.721.4979.0.

Diagnostic command (repro for others)

Get-WinEvent -LogName 'Microsoft-Windows-AppXDeploymentServer/Operational' -MaxEvents 500 |
  Where-Object { $_.Message -match 'codex' -and $_.LevelDisplayName -ne 'Verbose' } |
  Sort-Object TimeCreated |
  Format-Table @{n='Time';e={$_.TimeCreated.ToString('HH:mm:ss')}}, Id,
    @{n='Msg';e={($_.Message -split "`r?`n")[0]}} -AutoSize -Wrap

Note the SID on each Remove operation is the interactive user, not S-1-5-18.

Impact / workaround

Desktop GUI is unusable (Store-only; no standalone installer exists). The bundled CLI (~\AppData\Local\OpenAI\Codex\bin\...\codex.exe) still works as a workaround.

Possibly related

#34277, #24047, #33321, #28035, #27858, #14087 — several describe "silent exit after launch"; this report adds that the package is actually deprovisioned (not just the process exiting).

The exact process that calls RemovePackage wasn't captured; I can attach a Process Monitor trace of one install→launch→removal cycle on request.