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

Open 💬 2 comments Opened Jun 17, 2026 by matthew-es

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_

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