Codex App on Windows: sandbox setup fails when project folder owner is BUILTIN\Administrators

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

Version 26.623.141536 • Released 2026/07/07

What subscription do you have?

PLUS

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

On Windows 11 Pro 25H2, Codex App could not list files in a newly created project folder.

The visible error was:

windows sandbox: helper_unknown_error: setup refresh had errors

The sandbox log showed:

write ACE grant failed on G:\python\CodexP: SetNamedSecurityInfoW failed: 5
setup refresh completed with errors
setup error: setup refresh had errors

Codex CLI could read and write files in the same folder.
Normal applications could also read and write files.
However, Codex App failed before the PowerShell command itself was executed.

The project folder owner was:

BUILTIN\Administrators

After changing the owner to the current Windows user, Codex App could list files normally.

Command used:

takeown /F G:\python\CodexP /R /D Y

What steps can reproduce the bug?

see above

What is the expected behavior?

_No response_

Additional information

_No response_