How to Fix “Error While Loading Config – You Appear to Be Using a Native ECMAScript Module Configuration File”

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You’re deep into a project—maybe setting up ESLint, Webpack, or another JavaScript tool—when suddenly, your terminal throws this curveball: “Error while loading config – You appear to be using a native ECMAScript module configuration file”. Ugh, what does that even mean? Don’t stress! This error is more common than you think, and it’s totally fixable.

In this guide, we’ll break down what’s causing this error, why it’s popping up, and how you can solve it step-by-step. Whether you’re a coding newbie or a seasoned developer, we’ll keep it simple, friendly, and loaded with practical tips. By the end, you’ll be back to building awesome stuff without this pesky error slowing you down. Let’s dive in!

What Does This Error Mean?

First, let’s decode the message. The error “Error while loading config – You appear to be using a native ECMAScript module configuration file” is your tool’s way of saying, “Hey, I don’t know how to read this config file!” It’s tied to how JavaScript handles modules—specifically, the newer ECMAScript Modules (ESM) versus the older CommonJS system.

Here’s the quick version:

  • ECMAScript Modules (ESM): The modern way to write JavaScript, using import and export. It’s built into Node.js since version 12 and is the future of JS.
  • CommonJS: The old-school way, using require() and module.exports. Most tools—like ESLint or Webpack—grew up with this.

The error happens when your configuration file (like eslint.config.js or webpack.config.js) is written in ESM format, but the tool you’re using expects CommonJS. It’s like handing someone a fancy new smartphone when they only know how to use a rotary phone—they’re just not compatible yet!

This error often shows up with tools like ESLint (especially version 9+), but it can happen with others too. Don’t worry—we’ll show you how to fix it!

Why Does This Error Happen?

Before we jump to solutions, let’s figure out why this error crashes your workflow. Here are the usual suspects:

1. Newer Tool Versions

Tools like ESLint 9 (released in 2024) now support ESM config files by default. But if your setup—like your Node.js version or project settings—still expects CommonJS, you’ll hit this snag.

2. ESM Syntax in Config Files

If your config file uses import instead of require(), it’s an ESM file. Older tools or setups might choke on that because they’re stuck in CommonJS land.

3. Node.js Version Mismatch

Node.js supports ESM natively, but only if you tell it to (via package.json or file extensions). If your Node version or project setup isn’t ESM-ready, tools get confused.

4. Mixed Module Systems

Your project might mix ESM and CommonJS—like an ESM config file in a CommonJS app. Tools don’t always handle this mashup gracefully.

The good news? Once you spot the cause, fixing it is straightforward. Let’s get to it!

Image Suggestion: A cartoon of a puzzled developer holding two puzzle pieces labeled “ESM” and “CommonJS.”
Alt Text: “Developer confused by ESM and CommonJS mismatch in config error.”

How to Fix the Error: Step-by-Step Solutions

Time to roll up our sleeves and fix this! We’ve got four solid solutions—try them in order, or pick the one that matches your situation. Each comes with easy steps and examples.

Solution 1: Switch Your Config to CommonJS

The simplest fix? Rewrite your config file in CommonJS format, which most tools still love.

How to Do It:

  1. Open Your Config File: Find the file causing the error (e.g., eslint.config.js or webpack.config.js).
  2. Check the Syntax: Does it use import? Like this:
   import { somePlugin } from 'some-package';
   export default {
     rules: { 'no-unused-vars': 'error' }
   };
  1. Switch to CommonJS: Replace import with require() and export default with module.exports:
   const { somePlugin } = require('some-package');
   module.exports = {
     rules: { 'no-unused-vars': 'error' }
   };
  1. Test It: Run your command again (e.g., npx eslint . or npx webpack). Error gone? You’re set!

Why It Works:

Most tools—like ESLint 8 or Webpack 5—expect CommonJS by default. This aligns your config with what they’re ready to handle.

Solution 2: Tell Node.js It’s an ESM File

If you want to use ESM (it’s the future, after all!), you need to tell Node.js your config file is an ESM module.

How to Do It:

  1. Rename the File: Change the extension to .mjs (e.g., eslint.config.js becomes eslint.config.mjs).
  2. Keep ESM Syntax: Leave your import and export as-is:
   import { somePlugin } from 'some-package';
   export default {
     rules: { 'no-unused-vars': 'error' }
   };
  1. Update package.json (Optional): Add this to your package.json if the tool still complains:
   {
     "type": "module"
   }
  1. Run It: Try your command (e.g., npx eslint .). Fixed? Great!

Why It Works:

The .mjs extension or "type": "module" tells Node.js to treat the file as ESM, so tools that support it (like ESLint 9) can load it properly.

Image Suggestion: A file icon changing from .js to .mjs with a green checkmark.
Alt Text: “Renaming config file to .mjs to fix ECMAScript module error.”

Solution 3: Downgrade Your Tool’s Version

If the error came after updating a tool (like ESLint to 9.x), rolling back to an older version can dodge the ESM issue entirely.

How to Do It:

  1. Check Your Version: In your terminal, run:
   npx eslint --version


If it’s 9.x, let’s go back to 8.x.

  1. Uninstall the New Version:
   npm uninstall eslint
  1. Install an Older Version:
   npm install eslint@8.57.0
  1. Test It: Use your old CommonJS config and run:
   npx eslint .

Why It Works:

Older versions (like ESLint 8) don’t push ESM configs by default, so they play nice with CommonJS setups. It’s a quick fix if you’re not ready for ESM yet.

Solution 4: Update Node.js and Configure for ESM

Using an old Node.js version? Upgrading to a recent one and setting up ESM support can solve this for good.

How to Do It:

  1. Check Your Node Version: Run:
   node -v


If it’s below 14 (e.g., v12.x), let’s upgrade.

  1. Install NVM (Node Version Manager): Get it from GitHub, then:
   nvm install 18
   nvm use 18
  1. Set ESM in package.json: Add:
   {
     "type": "module"
   }
  1. Use ESM Config: Keep your import/export syntax and rerun your command.

Why It Works:

Node 14+ fully supports ESM, and setting "type": "module" ensures your project and tools align with the modern standard.

Common Scenarios and Quick Fixes

This error loves to show up in specific tools. Here’s how it looks—and what to do:

ESLint Projects

  • Problem: ESLint 9+ expects ESM configs (e.g., eslint.config.js).
  • Fix: Switch to CommonJS (Solution 1) or use .mjs (Solution 2).

Webpack Builds

  • Problem: webpack.config.js uses import but Webpack expects CommonJS.
  • Fix: Rewrite as CommonJS:
  const path = require('path');
  module.exports = {
    entry: './src/index.js',
    output: {
      path: path.resolve(__dirname, 'dist'),
      filename: 'bundle.js'
    }
  };

TypeScript Projects

  • Problem: tsconfig.json with ESM imports in a mixed setup.
  • Fix: Add "type": "module" to package.json and use .mjs for configs.

How to Avoid This Error in the Future

Prevention’s the name of the game! Here’s how to keep this error at bay:

1. Match Your Tool and Node Versions

Check your tool’s docs (e.g., ESLint’s guide) for Node compatibility before upgrading.

2. Pick a Module System

Decide upfront: ESM or CommonJS? Stick to one across your project to avoid confusion.

3. Test Configs Early

After writing a config, test it with a small command (e.g., npx eslint --version) to catch issues fast.

4. Stay Updated

Follow Node.js and tool changelogs (like Node’s blog) to know when ESM shifts happen.

Image Suggestion: A checklist with “Choose Module System” ticked off.
Alt Text: “Checklist to avoid ECMAScript module config errors.”

What If Nothing Works?

Still stuck? Don’t give up—try these:

  • Clear Cache: Run npm cache clean --force, delete node_modules, and reinstall with npm install.
  • Check Logs: Look at the full error output for clues—share it on Stack Overflow if needed.
  • Ask for Help: Drop a comment below with your setup, and I’ll dig in with you!

Why Fixing This Matters

You might think, “It’s just a config error—why bother?” Here’s why:

  • Smooth Workflow: A fixed config keeps your tools running without hiccups.
  • Future-Proofing: Embracing ESM prepares you for modern JavaScript trends.
  • Team Sync: If you’re collaborating, a working setup keeps everyone on track.

Final Thoughts

The “Error while loading config – You appear to be using a native ECMAScript module configuration file” error might feel like a coding roadblock, but it’s really just a sign your project needs a little TLC. Whether you switch to CommonJS, embrace ESM, or tweak your setup, you’ve got plenty of ways to fix it. Soon, you’ll be back to coding magic without this glitch slowing you down!

Ever run into this error? How did you solve it? Share your tips in the comments—I’d love to hear! And if this guide helped, pass it along to a friend wrestling with config woes.

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