# Last Windows Codex App Update Causing error sandbox **URL:** \ **Category:** Codex\ **Tags:** windows-app, codex-app\ **Created:** [August 22, 2026, 1:18am UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757 "2026-08-22T01:18:05Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![jhsn26](https://avatars.discourse-cdn.com/v4/letter/j/7bcc69/32.png) [@jhsn26](https://community.openai.com/u/jhsn26)\ **Post date:** [August 22, 2026, 1:18am UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/1 "2026-08-22T01:18:05Z")
The latest Codex desktop update is causing an error in the sandbox, this message appears. I tested a read-only operation (Get-Location and git status) and the sandbox failed before running the command, with the same error: helper\_unknown\_error: setup refresh had errors. So, the problem is still with the local Codex environment startup, not the project. ---
**Author:** ![QT](https://avatars.discourse-cdn.com/v4/letter/q/a587f6/32.png) [@QT](https://community.openai.com/u/QT)\ **Post date:** [August 22, 2026, 7:53am UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/2 "2026-08-22T07:53:02Z")
Same here. No files in any UE project can be edited in a new Chat. ---
**Author:** ![EricGT](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/ericgt/32/20571_2.png) [@EricGT](https://community.openai.com/u/EricGT)\ **Post date:** [August 22, 2026, 10:15am UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/3 "2026-08-22T10:15:56Z")
> [@jhsn26](#): > > setup refresh had errors Welcome to the forum! You are welcome to discuss Codex issues here. However, the official place to report and track them is the [OpenAI Codex GitHub issue tracker](https://github.com/openai/codex/issues). I asked ChatGPT to look for the closest related issue, and it identified: > > > \### What version of the Codex App are you using (From “About Codex” dialog)? > > Un…known > > \### What subscription do you have? > > ChatGPT Plus > > \### What platform is your computer? > > Windows 10 / Windows 11, Codex Windows desktop app > > \### What issue are you seeing? > > Codex Windows desktop app repeatedly fails with: > > helper\_unknown\_error: setup refresh had errors > > Previous Codex feedback ID: > 019ef48e-e421-7f93-bc11-aa7f3d42cac3 > > Current behavior: > > \* git status --short --untracked-files=all succeeds and shows no output. > \* git diff --cached --stat succeeds and shows no output. > \* git log -1 --oneline fails with helper\_unknown\_error. > \* Reading AGENTS.md fails with helper\_unknown\_error. > \* Reading scenes/main/main.gd fails with helper\_unknown\_error. > > Local PowerShell on the same machine can run git status, git diff, git log, and read AGENTS.md successfully, so the project files and Git repository appear to be fine. > > What I already tried: > > \* Rebooted Windows. > \* Removed and re-added the project in Codex. > \* Created new Codex threads. > \* Submitted feedback from the Codex app. > \* Checked %USERPROFILE%.codex\\config.toml. > \* Removed duplicate \[windows\] config entries. > \* Kept only: > \[windows\] > sandbox = "elevated" > \* Ran Codex as administrator. > \* The environment check succeeded once after fixing the duplicate config, but the next real task failed again with the same helper\_unknown\_error. > > Current project state: > > \* Worktree is clean. > \* Staging area is empty. > \* No files were modified. > \* No tests or Godot commands were run. > \* No git add or git commit was performed. > > This issue is blocking my work. I mainly use ChatGPT Plus for Codex, but Codex is currently unusable for this project. Please investigate the Windows sandbox/setup refresh failure. > > > \### What steps can reproduce the bug? > > Feedback ID: 019ef7e9-f772-7da1-8e0a-f793ee2ddebf > > \### What is the expected behavior? > > Codex should be able to complete setup refresh, read project files, and run basic git commands consistently. > > Expected: > > \* git log -1 --oneline should work. > \* AGENTS.md should be readable. > \* scenes/main/main.gd should be readable. > \* Codex should not fail during setup refresh before the task starts. > \* If the local Git worktree is clean and local PowerShell can read the files, Codex should be able to read them too. > > > \### Additional information > > Local PowerShell on the same machine can run git status, git diff, git log, and read AGENTS.md successfully. The project files and Git repository appear to be fine. > > What I already tried: > > \* Rebooted Windows. > \* Removed and re-added the project in Codex. > \* Created new Codex threads. > \* Submitted feedback from the Codex app. > \* Checked %USERPROFILE%.codex\\config.toml. > \* Removed duplicate \[windows\] config entries. > \* Kept only: > \[windows\] > sandbox = "elevated" > \* Ran Codex as administrator. > \* Environment check succeeded once, but the next real task failed again with helper\_unknown\_error. > > Current project state: > > \* Worktree is clean. > \* Staging area is empty. > \* No files were modified. > \* No tests or Godot commands were run. > \* No git add or git commit was performed. > > This is blocking my work. I mainly use ChatGPT Plus for Codex, but Codex is currently unusable for this project. Some of the issue replies note some workarounds. If that issue matches your problem, consider adding a 👍 reaction on the GitHub issue itself—not only on this forum topic. Reactions on GitHub can help the developers gauge the number of affected users. If it does not describe the same problem, search the [existing Codex issues](https://github.com/openai/codex/issues) for a closer match. If you cannot find one, open a new issue and include as much relevant detail as possible. ---
**Author:** ![bbourn](https://avatars.discourse-cdn.com/v4/letter/b/e480ec/32.png) [@bbourn](https://community.openai.com/u/bbourn)\ **Post date:** [August 22, 2026, 3:45am UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/4 "2026-08-22T03:45:53Z")
Codex version: 26.818.5229.0 Windows package: OpenAI.Codex\_26.818.5229.0\_x64\_\_2p2nqsd0c76g0 Problem: Codex cannot initialize its Windows sandbox. This prevents both ordinary sandboxed commands and Computer Use from running. Exact errors: - exec\_command: helper\_unknown\_error: setup refresh had errors - node\_repl: windows sandbox failed: helper\_unknown\_error: setup refresh had errors - Node kernel exits with code 1 / stdout\_eof before importing @oai/sky Minimal reproduction: 1. Open any local task in the Codex Windows app. 2. Attempt a simple sandboxed command such as Get-Location. 3. The command fails before process creation. 4. Reset the Node REPL and execute: nodeRepl.write(“node-repl-alive”) 5. The kernel exits during Windows sandbox setup. Already attempted: - Restarted Codex - Used Windows App Repair - Rebuilt the Codex runtime caches - Fully uninstalled and reinstalled Codex The failure persists after every attempt. Additional checks: - The CodexSandboxUsers local group exists. - CodexSandboxOffline and CodexSandboxOnline exist and are enabled. - The installed Codex package reports Status: OK. - Elevated commands still work, but normal sandboxed commands do not. Impact: Computer Use is completely unavailable, so I cannot finish UI-based application testing and evidence captures. Please advise whether there is a sandbox-reset procedure or collect this as a Windows Codex sandbox initialization defect. ---
**Author:** ![bbourn](https://avatars.discourse-cdn.com/v4/letter/b/e480ec/32.png) [@bbourn](https://community.openai.com/u/bbourn)\ **Post date:** [August 24, 2026, 11:15am UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/5 "2026-08-24T11:15:22Z")
Retested with Store build 26.818.8289.0. The defect persists unchanged. Computer Use’s Node kernel exits before @oai/sky loads with: “windows sandbox failed: helper\_unknown\_error: setup refresh had errors” A clean kernel reset then reports: “trusted Node process exited unexpectedly” ---
**Author:** ![Upasunda](https://avatars.discourse-cdn.com/v4/letter/u/e36b37/32.png) [@Upasunda](https://community.openai.com/u/Upasunda)\ **Post date:** [August 24, 2026, 1:10pm UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/6 "2026-08-24T13:10:11Z")
This can happen when codex fails to reassign ownership of .agents. Try checking: `$((Get-Acl -LiteralPath 'path/to/.agents').Owner)` it should correspond with: `[System.Security.Principal.WindowsIdentity]::GetCurrent().Name` I had an instance when it was owned by CodexSandboxOffline For me it was just a matter of reassigning ownership to myself again. So from an elevated powershell, just run: `icacls /path/to/.agents /setowner [System.Security.Principal.WindowsIdentity]::GetCurrent().Name` (or MACHINE/username) This solved the issue for me. ---
**Author:** ![bbourn](https://avatars.discourse-cdn.com/v4/letter/b/e480ec/32.png) [@bbourn](https://community.openai.com/u/bbourn)\ **Post date:** [August 25, 2026, 11:55am UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/7 "2026-08-25T11:55:50Z")
Thanks, @Upasunda — your suggestion uncovered some permissions issues, although correcting it did not fully restore the elevated sandbox. The repository and `.agents` were already owned by my Windows account, but the repository’s `.tmp` worktree directory and its descendants were owned by `CodexSandboxOffline`. I reassigned those to my account. I also found two explicit ACL entries for stale, unresolved SIDs on the repository root and `.agents`; I removed only those entries and preserved the current `CodexSandboxUsers` permissions. After verifying the ACLs and restarting Codex, the elevated sandbox still failed with: `windows sandbox failed: helper_unknown_error: setup refresh had errors` What finally restored Computer Use was changing `%USERPROFILE%\.codex\config.toml` to: ```auto [windows] sandbox = "unelevated" ``` Computer Use initialized successfully immediately afterward and was able to control a Windows desktop application. So the issue is operationally worked around, but I would not call the underlying elevated-sandbox problem fixed. According to the official OpenAI Windows sandbox documentation, `elevated` is preferred and `unelevated` is the weaker fallback mode. I plan to return to `elevated` once the setup-refresh problem is resolved. It is possible that I inadvertently caused the issue by granting access to folders from my primary project to a new project, but I can not confirm that on my own. ---
**Author:** ![GSEXPRESS](https://avatars.discourse-cdn.com/v4/letter/g/47e85d/32.png) [@GSEXPRESS](https://community.openai.com/u/GSEXPRESS)\ **Post date:** [August 27, 2026, 8:03am UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/8 "2026-08-27T08:03:14Z")
I experienced a related Windows elevated-sandbox failure, although the exact error signature was different. `Codex Build -> 26.820.7780.0` In my case, sandbox setup refresh reported `errors=[]`, but the command runner subsequently failed with `Access is denied (error 5)` while working with: ```auto C:\Users\Default\.codex\.sandbox\cwd ``` This caused runner startup timeouts and `apply_patch` failures. The recovery sequence that worked for me was: 1. Temporarily set: ```auto [windows] sandbox = "unelevated" ``` 1. Verified that `apply_patch` could create, read and delete a temporary probe file without changing Git status. 2. Completed only one carefully bounded action while in the weaker `unelevated` fallback mode. 3. Updated the Codex Windows app to the latest available version. 4. Installed the latest Windows updates. 5. Closed Codex, ChatGPT, VS Code and related background processes. 6. Used: **Windows Settings → Apps → Installed apps → Codex/ChatGPT → Advanced options → Repair** I selected **Repair** , not Reset. 1. Restarted the application and restored: ```auto [windows] sandbox = "elevated" ``` 1. Ran another non-destructive health check. Final result: ```auto SANDBOX MODE: elevated APPLY_PATCH: PASS CREATE: PASS READ: PASS DELETE: PASS ERROR: None ``` Git status remained unchanged. I cannot confirm whether the successful recovery came from the Codex update, Windows update, App Repair, or their combination. Therefore, I would describe this as a confirmed recovery sequence—not a proven universal fix. I also would not recommend copying ownership or `icacls` commands unless the affected user’s logs and read-only ACL inspection identify that exact problem. My failure involved the sandbox runner and `C:\Users\Default`, not `.agents` ownership. A useful approach is to give the relevant logs to your own Codex agent and ask it to: - separate the primary failure from consequential timeout errors; - begin with read-only diagnostics; - preserve repository state; - recommend the least-destructive supported recovery; - avoid ACL changes, folder deletion or App Reset without explicit approval. ---
**Author:** ![OpenAI\_Support](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/openai_support/32/561845_2.png) [@OpenAI\_Support](https://community.openai.com/u/OpenAI_Support)\ **Post date:** [September 16, 2026, 3:27pm UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/9 "2026-09-16T15:27:43Z")
Hey everyone, This was resolved in the subsequent windows app updates. We will close this thread now. Apologies for delayed response. ---
**Author:** ![Prashant\_Pardesi](https://avatars.discourse-cdn.com/v4/letter/p/f9ae1b/32.png) [@Prashant\_Pardesi](https://community.openai.com/u/Prashant_Pardesi)\ **Post date:** [September 16, 2026, 3:27pm UTC](https://community.openai.com/t/last-windows-codex-app-update-causing-error-sandbox/1391757/10 "2026-09-16T15:27:50Z")