Windows: node_repl cannot launch, CreateProcessAsUserW failed: 5, breaking Chrome plugin

Open 💬 2 comments Opened Jun 17, 2026 by matthew-es
💡 Likely answer: A maintainer (github-actions[bot], contributor) responded on this thread — see the highlighted reply below.

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

26.611.62324

What subscription do you have?

Pro $100

What platform is your computer?

Microsoft Windows NT 10.0.22631.0 x64

What issue are you seeing?

Title:
Windows: node_repl cannot launch, CreateProcessAsUserW failed: 5, breaking Chrome plugin

Summary:
Codex Desktop on Windows can run normal shell_command / PowerShell commands, but the Node REPL runtime fails globally at startup with:

windows sandbox failed: runner error: CreateProcessAsUserW failed: 5

This prevents the Chrome plugin from working, because Chrome automation routes through node_repl.

Environment:

  • OS: Windows
  • Codex Desktop
  • Shell in Codex thread: Windows PowerShell 5.1.22621.6133
  • Sandbox mode: workspace-write
  • Windows sandbox config: elevated
  • Approval policy: on-request
  • js_repl: true
  • Chrome plugin enabled: true
  • Browser plugin enabled: true
  • Chrome extension status in Codex settings: Connected
  • Workspace dependencies current version shown in settings: 26.614.11602
  • Browser/Chrome plugin app version shown in config env: 26.609.41114

Relevant config:
[features]
js_repl = true

[windows]
sandbox = "elevated"

[plugins."chrome@openai-bundled"]
enabled = true

[mcp_servers.node_repl]
command = 'C:\Users\matth\AppData\Local\OpenAI\Codex\runtimes\cua_node\789504f803e82e2b\bin\node_repl.exe'
startup_timeout_sec = 120

Observed behavior:
A minimal node_repl runtime check fails before executing any JavaScript:

nodeRepl.write('runtime ok')

The tool crashes with:

node_repl kernel exited unexpectedly
node_repl diagnostics: {"kernel_status":"running","kernel_stderr_tail":"windows sandbox failed: runner error: CreateProcessAsUserW failed: 5","reason":"stdout_eof"}

The same error occurs when trying to bootstrap the Chrome plugin:

const { setupBrowserRuntime } = await import('C:/Users/matth/.codex/plugins/cache/openai-bundled/chrome/26.609.71450/scripts/browser-client.mjs');
await setupBrowserRuntime({ globals: globalThis });
globalThis.browser = await agent.browsers.get('extension');
nodeRepl.write(await browser.documentation());

Result:
node_repl kernel exited unexpectedly
windows sandbox failed: runner error: CreateProcessAsUserW failed: 5

Scope:
This is not limited to a projectless thread. I tested in:

  • A projectless Codex thread under Documents\Codex
  • A normal trusted project workspace: C:\Users\matth\Documents\building\insightalpha2

node_repl fails in both places with the same CreateProcessAsUserW failed: 5 error.

Important distinction:
Normal shell/PowerShell commands inside Codex do work. For example, Codex can read config.toml and run PowerShell commands. The failure appears specific to node_repl / the bundled cua_node runtime launch path, not all local command execution.

Troubleshooting already tried:

  • Set js_repl = true
  • Restarted Codex
  • Reinstalled / reset Codex Workspace dependencies
  • Updated Codex
  • Tested with @chrome explicitly tagged
  • Tested in a normal trusted project workspace
  • Verified Chrome plugin files exist, including browser-client.mjs
  • Verified Chrome extension shows Connected in Codex settings
  • Verified Chrome does not need to be default browser
  • Checked Windows Security:
  • Protection history clean except unrelated “potentially unwanted apps are turned off” notice
  • Quick scan found 0 threats
  • Controlled Folder Access is off
  • Reputation-based protection / potentially unwanted app blocking is off
  • Exploit Protection program settings show no Codex, OpenAI, node, node_repl, node.exe, or codex-computer-use.exe entries

Expected behavior:
node_repl should launch and allow a minimal command like:

nodeRepl.write('runtime ok')

Once node_repl launches, the Chrome plugin should be able to connect to the already-connected Chrome extension.

Actual behavior:
node_repl fails globally at startup with CreateProcessAsUserW failed: 5, and Chrome automation cannot be used.

Notes:
In my case, normal PowerShell/shell_command tools work. The failure appears narrower: node_repl / Chrome plugin helper launch fails, while regular shell commands succeed.

What steps can reproduce the bug?

Feedback ID: 019ed1f3-3782-7180-88b9-25348cf0daa3

What is the expected behavior?

_No response_

Additional information

_No response_

View original on GitHub ↗

2 Comments

github-actions[bot] contributor · 2 months ago

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

  • #27792
  • #27313
  • #28033
  • #28005

Powered by Codex Action

bradleykemp · 2 months ago

I can reproduce this on Windows with Codex Desktop 26.611.x.

Same pattern:

  • Basic shell sandbox works: whoami /user -> pc1\codexsandboxoffline
  • Minimal Node REPL test fails before user JS runs:

nodeRepl.write('node_repl smoke ok');

  • Error:

windows sandbox failed: runner error: CreateProcessAsUserW failed: 5

  • Fresh .codex profile did not fix it
  • Codex reinstall did not fix it
  • Bitdefender uninstall did not fix it
  • Smart App Control off
  • Memory Integrity off

This also breaks the in-app browser, because browser bootstrap depends on node_repl.

Additional details from my repro:

  • Fresh .codex folder was tested and still failed.
  • Restoring old .codex initially caused:

CreateProcessWithLogonW failed: 1326
because .sandbox-secrets no longer matched regenerated CodexSandboxOffline/Online passwords.

  • Renaming .sandbox-secrets and letting Codex regenerate it fixed the 1326 error.
  • After that, basic shell sandbox worked again, but node_repl returned to:

CreateProcessAsUserW failed: 5

  • CodexSandboxOffline and CodexSandboxOnline exist and are enabled.
  • CodexSandboxOffline is in CodexSandboxUsers.
  • Basic shell commands run as:

pc1\codexsandboxoffline

  • The issue is specific to node_repl / bundled cua_node launch path, not all sandboxed commands.
  • Chrome extension being installed or not installed did not affect the Node REPL smoke test.
  • System Node.js installation does not appear relevant; Codex is using bundled node/node_repl under:

C:\Users\bradl\AppData\Local\OpenAI\Codex\runtimes\cua_node\...

Minimal repro:

  1. Start Codex Desktop on Windows.
  2. Run a basic shell command:

whoami /user
Result: succeeds as pc1\codexsandboxoffline.

  1. Run Node REPL smoke test:

nodeRepl.write('node_repl smoke ok');
Result:
node_repl kernel exited unexpectedly
windows sandbox failed: runner error: CreateProcessAsUserW failed: 5