›_ Codex Issues
Codex Issues / #32487

Windows sandbox fails with Smart App Control enabled because unsigned node_repl.exe is blocked

Open 💬 4 comments Opened Jul 11, 2026 by pkempec
💡 Likely answer: A maintainer (github-actions[bot], contributor) responded on this thread — see the highlighted reply below.

Summary

Codex Desktop cannot create a Windows sandbox on Windows 11 Pro with Smart App Control enabled.

The sandbox fails before PowerShell starts with:

windows sandbox: helper_unknown_error: setup refresh had errors

Investigation shows Windows Code Integrity blocks an unsigned runtime executable (node_repl.exe) while the main codex.exe is properly signed.

Environment

  • Codex Desktop: 26.707.3748.0
  • Windows 11 Pro 24H2 (Build 26200)
  • Installed from OpenAI
  • Personal PC (not enterprise managed)

Security:

  • SmartAppControlState: On
  • DeviceGuardCodeIntegrityPolicyEnforcementStatus: EnforcementMode
  • DeviceGuardUserModeCodeIntegrityPolicyEnforcementStatus: EnforcementMode

Reproduction

  1. Open Codex Desktop.
  2. Create a new task.
  3. Sandbox initialization immediately fails.

Actual result

windows sandbox: helper_unknown_error: setup refresh had errors

Diagnostics

Windows Code Integrity logs:

codex.exe attempted to load ...\\OpenAI\\Codex\\runtimes\\cua_node\\...\\bin\\node_repl.exe that did not meet Enterprise signing level requirements or violated code integrity policy.

Authenticode:

  • codex.exe: Valid signature (OpenAI OpCo, LLC)
  • node_repl.exe: Status = NotSigned

Virtualization is enabled and functioning (VM Monitor Mode Extensions, SLAT, DEP, Virtualization Enabled in Firmware).

Expected

Either:

  • sandbox initializes successfully under Smart App Control, or
  • Codex reports a descriptive error indicating Windows Code Integrity blocked an unsigned runtime executable.

The generic helper_unknown_error made diagnosis difficult.

If node_repl.exe is expected to execute under Smart App Control / WDAC, it may need to be Authenticode signed or otherwise packaged in a compatible way.

View original on GitHub ↗

4 Comments

github-actions[bot] contributor · 1 month ago

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

  • #31848

Powered by Codex Action

loop-smith · 1 month ago

Additional evidence from the affected Windows machine (2026-07-11 PDT):

  • Installed package: OpenAI.Codex_26.707.3748.0_x64__2p2nqsd0c76g0; AppX status Ok, SignatureKind=Store.
  • Parent codex.exe Authenticode: Valid, signer OpenAI OpCo, LLC.
  • The package itself contains app\resources\cua_node\bin\node_repl.exe, and the extracted runtime copy is byte-identical:
  • SHA-256 231C65995AD196161371105117CC7AD33FD39063EE3F05A913586487D3D0BE9D
  • size 14,051,328 bytes
  • Authenticode NotSigned; no signer or version/product metadata
  • Adjacent node.exe is validly signed by the OpenJS Foundation, isolating this to the custom node_repl.exe packaging.
  • Runtime manifest identifies node_repl_archive_path=20260707.2/node_repl-20260707.2-x86_64-pc-windows-msvc.zip and runtime_archive_version=0.0.3/20260708050802-66a5641b5362-pr-1103797.
  • Code Integrity logged correlated events 3033, 3077, 3089, and 3118 on six load attempts. Event 3077 names VerifiedAndReputableDesktop (policy GUID {0283ac0f-fff1-49ae-ada1-8a933130cad6}) with status 0xc0e90002; event 3089 reports TotalSignatureCount=0. Latest observed block was 2026-07-11 15:12:40 PDT.
  • Microsoft Defender recorded zero threat/detection/action events in the checked 14:30–15:16 PDT window. This is SAC signing/reputation enforcement, not a malware verdict.
  • The supported Microsoft Store update path was checked (9PLM9XGG6VKS); winget returned No newer package versions are available from the configured sources.

A repair/cache clear cannot resolve this build: it restores the same unsigned binary shipped inside the package. Please Authenticode-sign node_repl.exe, regenerate the cua_node archive, publish a new Store build, and surface the Code Integrity block explicitly instead of helper_unknown_error. Smart App Control remains enabled; no local trust bypass was applied.

loop-smith · 1 month ago

Post-install Beta result from the same affected machine:

  • Microsoft Store installed a separate package, OpenAI.CodexBeta_26.707.3351.0_x64__2p2nqsd0c76g0, alongside stable OpenAI.Codex_26.707.3748.0_x64__2p2nqsd0c76g0.
  • Beta is the lower AppX version (26.707.3351.0 versus stable 26.707.3748.0).
  • Beta bundles the exact same app\resources\cua_node\bin\node_repl.exe as stable:
  • SHA-256 231C65995AD196161371105117CC7AD33FD39063EE3F05A913586487D3D0BE9D
  • size 14,051,328 bytes
  • Authenticode NotSigned
  • Beta's cua_node/manifest.json is identical: Node 24.14.0, node_repl archive 20260707.2, runtime 0.0.3/20260708050802-66a5641b5362-pr-1103797.
  • Beta registered successfully at 2026-07-11 15:23:28 PDT and starts, but startup alone does not load the helper. No new Code Integrity event was generated after registration because the known-unsigned executable was not run directly.
  • The Store Beta therefore does not contain a signing fix. It cannot satisfy Smart App Control's acceptance gate; a newly signed helper/archive remains required.
alexandrrecardoso-sys · 1 month ago

Duplicate of #32487