---
title: "A critical error: Chromium revision is not downloaded."
date: 2020-03-17T11:34:00-04:00
author: John Morton
canonical_url: "https://supergeekery.com/blog/a-critical-error-chromium-revision-is-not-downloaded"
section: Blog
---
# A critical error: Chromium revision is not downloaded.

*March 17, 2020* by John Morton

I have been trying to get [critical](https://github.com/addyosmani/critical) to work on my Mac but kept getting the following error when my webpack configuration hit the point where it was trying to configure the Critical CSS.

```
Error: Chromium revision is not downloaded. Run "npm install" or "yarn install" at Launcher.launch (/Users/john/Sites/craft-w-webpack/node_modules/puppeteer/lib/Launcher.js:119:15)
```

I tried fixing this by following the instructions, `npm install`, but the error continued to happen.

The path to getting this fixed had several steps and I thought they might be helpful to my future self or someone else, so I'm documenting them here.

## Clue 1: A new MacBook

The work I'm doing is on a new MacBook Pro. In setting up the machine, I'd installed all the various dev tools I use, including Docker. 

## Clue 2: Docker is required for Critical

Even though I installed Docker, I'm not a regular Docker user. I wanted to have it installed because using Docker is something I aspire to do "when I get to it." Even though I don't use it, Docker is a requirement when using [HTML Critical Webpack Plugin](https://github.com/anthonygore/html-critical-webpack-plugin), the plugin extracts critical CSS when using webpack. Having it installed seemed like a necessary thing.

## My theory: I missed installation errors

When doing my initial installation of the Node packages in my project, I must have missed installation errors along the way. Normally when installing `critical` and `html-critical-webpack-plugin`, Chromium would be installed using Docker. You can read the Docker requirement [here in the documentation](https://github.com/anthonygore/html-critical-webpack-plugin#development). 

I had Docker installed, but it turns out I had never actually opened the program since installing it. Upon initial installation of Docker on a Mac, you are prompted with several dialog boxes that you need to go through before it will actually run. So, I opened Docker on my Mac and click through the dialog boxes and then Docker was running on my machine.

I thought I'd figured out the problem.

I then tried to `npm install` in my project. I thought this would fix the issue. The installation process completed, but when I tried to build my webpack project, I hit the same error. 

## A clean install

After a few moments of frustration, I decided that perhaps wiping out my `node_modules` directory completely and forcing a full installation of every package would be worth a try. 

As I watched the installation process go through its paces, I was pleased to see it hit a point where Chromium was being installed. This is the piece I must have missed on the initial installation of packages. When this reinstallation of my node modules finished, I tried to build my webpack production configuration again and the critical CSS was generated without a hiccup. Success!