In my case I was struggling to compile node-sass on a Centos7 and I solved removing node-sass and putting sass instead.

npm uninstall node-sass
npm install sass
npm install sass-loader^8

NPM downloads dependency packages to modules inside the module if they are in different version then one in your package.json but sometimes it downloads latest version od dependant package (dunno why) into a module..

for example you can have sass-loader: 2.X in your package.json, and a module XXXX wich also has sass-loader: * in its dependency packages (you cn check that in package.json inside that XXXX module) npm will download sass-loader 2.X for you, and sass-loader: 3.X for the XXXX package - youl get an error.

Quick fix is to remove that additional package from XXXX/node_modules You can also check what package version the XXXX module use and try to use the same version in your project.

In my case font-awesome-sass-loader@2.0.1 with project.json:

  "dependencies": {
    "css-loader": "*",
    "sass-loader": "*",
    "style-loader": "*"
  },

downloaded sass-loader: 3.0.0

while npm downloaded sass-loader: 2.0.0 according to project.json in my project:

"style-loader": "2.0.0"

I removed node_modules/font-awesome-sass-loader/node_modules/ and it fixed the problem.

Ran yarn remove sass-loader

And then installed specifically version 10 as yarn add sass-loader@10. This totally solved the issue in "vue": "~2.6.12",

The command yarn add sass-loader installs version 11, which happens not to be compatible with Webpack version 4 and below. The current Vue CLI V4 uses Webpack v4.

You will have to wait until Vue CLI V5 (will use Webpack 5) is released (currently in Beta) in order to use sass-loader v12. Alternatively, you can update to Webpack 5, but be sure to read the CHANGELOG.

When using Webpack version 4, the default in Vue CLI 4. You need to make sure your loaders are compatible with it. Otherwise you will get errors about conflicting peer dependencies. In this case you can use an older version of the loader that is still compatible with Webpack 4.

# Sass
npm install -D sass-loader@^10 sass

Still not working?

Delete folder node_modules

npm install

Know more

Same here. Downgrading to the following versions helped: "sass": "^1.38.0", "sass-loader": "^10.2.0",

I had the same problem here with css-loader v6. Downgrading to v5 seems to work:

"css-loader": "^5.1.1"

style-loader v3 also dropped support for Webpack 4.

Your package.json entry should look like this:

"style-loader": "^2.0.0"

This solved for me, for similar problem with Sass:

1. add to package.json in devDependencies: "sass-loader": "7.3.1",
2. npm i -D sass or yarn add sass --dev
3. remove node_modules
4. npm install or yarn depending on your package manager

My configuration:

  "devDependencies": {
    "@vue/cli-plugin-babel": "~4.5.0",
    "@vue/cli-plugin-eslint": "~4.5.0",
    "@vue/cli-service": "~4.5.0",
    "babel-eslint": "^10.1.0",
    "eslint": "^6.7.2",
    "eslint-plugin-vue": "^6.2.2",
    "sass": "^1.32.6",
    "sass-loader": "7.3.1",
    "vue-template-compiler": "^2.6.11"
  },

Similar to what @KostDM said, in my case it seems like sass-loader@11.0.0 doesn't work with vue@2.6.12.

I installed sass-loader@10.1.1 and it worked like a charm again.

In your package.json:

"sass-loader": "^10",

Yesterday I found a problem after upgrading sass-loader to the latest version.

If using yarn, you can downgrade sass-loader. Use yarn add sass-loader@^10.1.1 it work.

I had the same problem resolved by downgrading sass-loader to 10.1.1. I am using @vue/cli 4.5.8 that includes webpack@4.46.0.

From v11.0.0 of sass-loader and v8.0.0 of less-loader, the

minimum supported webpack version is 5

• sass-loader v11.0.0 release notes
• less-loader v8.0.0 release notes

For me it helped to downgrade postcss-loader

+ "postcss-loader": "^4.2.0",
- "postcss-loader": "^5.0.0",

Downgrading the sass-loader to ^10.0.0 worked for me, but on a fresh Nuxt.js CLI application I had to also install Sass with:

npm i sass

To downgrade, you can remove the node_modules folder and to add, run this in your terminal:

npm i sass-loader@10 

This will install the newest 10 version of sass-loader.

And after all, again install all dependencies:

npm i

EDIT

Sass-loader versions higher than 10 requires webpack 5