[Windows] 26.915.4065.0 fails after updates; staging accumulates until sandbox-service stop and cleanup

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

26.915.4065.0 (Microsoft Store/MSIX, x64)

What subscription do you have?

Not specified in this report

What platform is your computer?

Windows, x64. Exact Windows edition/build not recorded.

What issue are you seeing?

Codex fails to open after every update on my machine. Restarting Windows has sometimes helped previously, but did not resolve the latest occurrence on September 20, 2026. The startup error is:

Unable to locate the Codex CLI binary or required runtime components.

After closing the app, a codex-windows-sandbox-service process remained in session 0. It was running from the installed OpenAI.Codex_26.915.4065.0_x64__2p2nqsd0c76g0 package, under app\resources\codex-windows-sandbox-service.exe.

%LOCALAPPDATA%\OpenAI\Codex\bin contained 12 directories named .staging-247581e40ee272fb-*, with timestamps in two groups on September 20 (12:29 and 14:28), but no final 247581e40ee272fb directory. An older .staging-52366fb4fdb365a8-* directory and older final directories 4fe45441001f7a41 and eab8377aebac6c07 were also present.

This prevents using the application after updates and requires manual recovery.

What steps can reproduce the bug?

1. Update the installed Codex Windows desktop app.
2. Try to open Codex.
3. On this machine, startup fails with the missing CLI/runtime error; repeated attempts leave multiple staging directories.
4. Restarting Windows is not a reliable recovery method.

This is my observed pattern, not a minimal deterministic reproduction on a clean machine.

What is the expected behavior?

Codex should start normally after updates and recover safely from interrupted runtime staging. Users should not need to terminate a background service, manually clean runtime folders, or maintain a repair script just to launch the app.

Additional information

Recovery observed

Following troubleshooting instructions to stop the remaining sandbox-service process, remove only .staging-* directories under %LOCALAPPDATA%\OpenAI\Codex\bin, and relaunch Codex, the app opened successfully. The subsequent directory listing contained:

247581e40ee272fb
73fd6465d9c76545

Both were timestamped September 20 at 14:32, with no remaining staging directories in that listing. The recovery procedure did not call for deleting .codex or normal hash-named runtime directories.

Stopping the process and cleaning staging were performed together, so this does not establish which action was necessary or prove that the service held a file lock.

Related reports and limits

Related: #45858 and #45593. This is an additional report on the newer 26.915.4065.0 build, with before/after directory observations and successful manual recovery.

The symptoms suggest a related runtime staging/finalization problem, but I have not captured a local rename_staging / EPERM log or a file-handle trace for this occurrence. Those error details are from the related reports and should not be treated as confirmed logs from my machine.

Please investigate the lifecycle of the sandbox-service process during updates and startup, runtime staging/finalization, and automatic recovery from abandoned staging directories.

Start with the Windows desktop app update and startup path, including app\resources\codex-windows-sandbox-service.exe and runtime directories under %LOCALAPPDATA%\OpenAI\Codex\bin. Reproduce the update failure if possible and inspect how the sandbox service and .staging-* directories are handled. Done means interrupted staging is recovered automatically and the app starts without manual process termination or cleanup.