Codex Desktop 26.825.4187.0 hangs on startup on Windows — background processes start but no GUI window appears

Description

Codex Desktop does not display any GUI window on Windows.

When launching Codex, multiple Codex background processes are created successfully, but no window appears. Codex is also absent from Alt+Tab.

Codex CLI works normally.

Environment

• OS: Windows 11 x64
• Codex Desktop: 26.825.4187.0
• Package: OpenAI.Codex_26.825.4187.0_x64__2p2nqsd0c76g0
• Package status: Ok
• SignatureKind: Store
• Codex CLI: 0.150.1

Steps to reproduce

1. Launch Codex Desktop from the Start menu.
2. Wait for the application to start.
3. Multiple Codex processes appear in Task Manager.
4. No GUI window appears.
5. Codex does not appear in Alt+Tab.

The same behavior occurs when running:

codex app

The CLI prints:

Opening workspace C:\Users\<username> in the Desktop app...

but no Desktop window appears.

Desktop log

The latest startup log stops almost immediately after:

2026-08-29T06:20:09.280Z info [sparkle] in_app_updates_policy_wait_started timeoutMs=300000
2026-08-29T06:20:09.281Z info Launching app agentRunId=null allowDebugMenu=false allowDevtools=false allowInspectElement=false buildFlavor=prod enableSparkle=false enableUpdater=true nodeEnv=undefined packaged=true platform=win32
2026-08-29T06:20:09.370Z info Appshot hotkey inactive configured=true enabled=false platform=win32

There are no subsequent window initialization messages.

Windows Error Reporting

Windows Error Reporting records:

Event ID: 1001
Event name: MoAppHang

Problem signature includes:

P1: OpenAI.Codex_26.825.4187.0_x64__2p2nqsd0c76g0
P2: praid:App
P3: 151.0.7922.174

AppModel Runtime

Microsoft-Windows-AppModel-Runtime/Admin does not report an application launch failure. It successfully:

• Creates the Codex process (Event 201)
• Creates the Desktop AppX container (Event 210)
• Adds the process to the AppX container (Event 211)

Therefore the MSIX/AppX launch itself appears to succeed.

Troubleshooting already attempted

• Restarted Windows
• Terminated all Codex processes
• Repaired Codex from Windows Settings
• Attempted Windows app Reset (Windows reported that the app could not be reset)
• Completely uninstalled Codex
• Restarted Windows
• Reinstalled Codex
• Launched from Start menu
• Launched with codex app
• Launched through shell:AppsFolder
• Waited more than 5 minutes
• Verified AppXSvc is running
• Verified InstallService is running
• Verified the Codex AppX package status is Ok

The problem persists after a clean reinstall.

Additional observation

codex features list reports:

in_app_updates    stable    true

I also tested:

codex app --disable in_app_updates

However, the Desktop log still reports:

in_app_updates_policy_wait_started timeoutMs=300000
enableUpdater=true

So the CLI feature override does not appear to affect the Desktop application's updater initialization.

Expected behavior

Codex Desktop should create and display its main GUI window.

Actual behavior

Codex starts multiple background processes but never creates a visible window and eventually produces a MoAppHang report.

Reproduce the hang on Windows 11 by launching Codex Desktop from the Start menu and with codex app, then inspect the startup log after in_app_updates_policy_wait_started. Use the reported AppModel Runtime and Windows Error Reporting events to narrow the failure. Done means the Desktop application creates a visible GUI window and no longer produces a MoAppHang report.