Windows Store Codex App crashes after update: sandbox ACL setup fails on WindowsApps path

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

26.313.5234.0

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

After the recent Microsoft Store update, Codex App on Windows consistently crashes or flash-exits during startup / early session initialization.

I had an earlier, separate issue on 2026-03-19 where the CLI and app-side model/version state did not match. That issue is different and was resolved. The current crashes happen even after the CLI side is stable.

The current failure appears to be in the Windows sandbox setup path used by the Store app build. My local sandbox log shows the app attempting to grant read ACLs on its own packaged resources under:

C:\Program Files\WindowsApps\OpenAI.Codex_26.313.5234.0_x64__2p2nqsd0c76g0\app\resources

The relevant errors are:

• grant read ACE failed ... SetNamedSecurityInfoW failed: 5
• setup error: read ACL run had errors

Relevant local log lines:

• C:\Users\Zhuyixiang\.codex\.sandbox\sandbox.log around local time 2026-03-19 22:44:52
• store helper path logged at line 82122
• ACL failure logged at line 82155
• setup failure logged at line 82157

This looks like the Windows Store app runtime is trying to mutate ACLs on the protected WindowsApps package path and then failing hard.

What steps can reproduce the bug?

1. Install or update Codex App from Microsoft Store to version 26.313.5234.0.
2. Launch Codex App on Windows.
3. Start a normal session (for me this happened in E:\Quant).
4. The app crashes / flash-exits during startup or early session initialization.
5. Inspect C:\Users\Zhuyixiang\.codex\.sandbox\sandbox.log.
6. Observe grant read ACE failed ... SetNamedSecurityInfoW failed: 5 followed by setup error: read ACL run had errors.

Notes:

• Codex CLI 0.115.0-alpha.27 remains stable on the same machine.
• The regression started after the Store app updated yesterday (relative to 2026-03-19).

What is the expected behavior?

The app should launch and initialize its sandbox helpers successfully on Windows. It should not crash while trying to grant ACLs on its own Microsoft Store package resources, and it should avoid touching protected WindowsApps paths in a way that causes startup failure.

Additional information

Additional context:

• This appears distinct from the earlier CLI/app model-version mismatch issue seen the same day.
• Current local config includes [windows] sandbox = "elevated".
• Similar public Windows sandbox reports exist, including a Reddit report with the same class of WindowsApps / ACL failure and several GitHub issues for Windows sandbox instability.
• I can provide the relevant sandbox.log excerpt if needed.