---
title: "Common Errors"
description: "Troubleshoot common issues encountered when running Unlighthouse scans, including browser connection and environment problems."
canonical_url: "https://unlighthouse.dev/guide/guides/common-errors"
last_updated: "2026-07-05T10:28:51.965Z"
---

Solutions for frequently encountered issues when running Unlighthouse scans. Ensure you're using the latest version before troubleshooting.

<tip>

For general debugging techniques, see the [Debugging Guide](/guide/guides/debugging).

</tip>

## `connect ECONNREFUSED 127.0.0.1:<port>`

**Example**

> Error: Unable to launch browser for worker, error message: connect ECONNREFUSED 127.0.0.1:51667

This error is thrown when Chromium is unable to launch. This happens when puppeteer is unable to connect to the browser.
This can be from a number of reasons:

- The environment is not configured correctly, likely when using Windows and WSL.
- You have a firewall or antivirus blocking Chrome or Chromium from launching or connecting to the required port.
- You are using an unsupported version of Chrome or Chromium.

**Windows and WSL Solution**

- Install Puppeteer on WSL following the [documentation](https://pptr.dev/troubleshooting#running-puppeteer-on-wsl-windows-subsystem-for-linux).
- Install Chrome in WSL following the [documentation](https://learn.microsoft.com/en-us/windows/wsl/tutorials/gui-apps#install-google-chrome-for-linux).

**Other Environments**

- You can try disabling the system Chrome, instead using the fallback.

```ts
import { defineUnlighthouseConfig } from 'unlighthouse/config'

export default defineUnlighthouseConfig({
  chrome: {
    useSystem: false,
  },
})
```

## Can't stop the scan with `Ctrl+C`

Unlighthouse keeps running after a scan so you can browse the dashboard. Press `Ctrl+C` in the terminal to stop it; this shuts down the dev server and closes Chrome.

If `Ctrl+C` does nothing, you are almost certainly running inside **Git Bash (MinTTY)** on Windows. MinTTY does not forward `Ctrl+C` to native console programs such as Node, so the process keeps running and you have to kill it from Task Manager.

**Solutions**

- Wrap the command with [winpty](https://github.com/rprichard/winpty), which ships with Git for Windows:

```bash
winpty npx unlighthouse --site example.com
```

- Or run the command from **PowerShell**, **Command Prompt**, or **Windows Terminal** instead of Git Bash, where `Ctrl+C` works as expected.