Q:

Laravel 6: npm run watch does not work after installing vue auth

I am using Laravel 6. After installing ui vue --auth I am not able to compile SASS files using npm run watch.
I got a long list of errors:
ERROR in ./resources/sass/app.scss
Module build failed (from ./node_modules/css-loader/index.js):
ModuleBuildError: Module build failed (from ./node_modules/sass-loader/dist/cjs.js):
ValidationError: Invalid options object. Sass Loader has been initialized using an options 
object that does not match the API schema.
- options has an unknown property 'outputStyle'. These properties are valid:
object { implementation?, sassOptions?, prependData?, sourceMap?, webpackImporter? }
at validate (/Applications/MAMP/htdocs/blog/node_modules/sass-loader/node_modules/schema- 
utils/dist/validate.js:85:11)
at Object.loader (/Applications/MAMP/htdocs/blog/node_modules/sass- 
loader/dist/index.js:36:28)
at /Applications/MAMP/htdocs/blog/node_modules/webpack/lib/NormalModule.js:316:20
at /Applications/MAMP/htdocs/blog/node_modules/loader-runner/lib/LoaderRunner.js:367:11
at /Applications/MAMP/htdocs/blog/node_modules/loader-runner/lib/LoaderRunner.js:233:18
at runSyncOrAsync (/Applications/MAMP/htdocs/blog/node_modules/loader- 
runner/lib/LoaderRunner.js:143:3)
at iterateNormalLoaders (/Applications/MAMP/htdocs/blog/node_modules/loader- 
runner/lib/LoaderRunner.js:232:2)
at /Applications/MAMP/htdocs/blog/node_modules/loader-runner/lib/LoaderRunner.js:205:4
at /Applications/MAMP/htdocs/blog/node_modules/enhanced- 
resolve/lib/CachedInputFileSystem.js:85:15
at processTicksAndRejections (internal/process/task_queues.js:79:11)
@ ./resources/sass/app.scss

My package.json file looks as following:
"devDependencies": {
        "axios": "^0.19",
        "bootstrap": "^4.0.0",
        "cross-env": "^5.1",
        "jquery": "^3.2",
        "laravel-mix": "^4.0.7",
        "lodash": "^4.17.13",
        "popper.js": "^1.12",
        "resolve-url-loader": "^2.3.1",
        "sass": "^1.20.1",
        "sass-loader": "^8.0.0",
        "vue": "^2.5.17",
        "vue-template-compiler": "^2.6.10",
        "webpack": "^4.42.0"
    }

My webpack.mix.js
const mix = require('laravel-mix');

mix.js('resources/js/app.js', 'public/js')
   .sass('resources/sass/app.scss', 'public/css');

I already removed node_modules and reinstalled it, but I could not solve the problem.

A:

There is an compatibility issue with sass-loader 8.0.0
You have to roll back to 7.x versions.
try to run those commands:
npm uninstall --save-dev sass-loader
npm install --save-dev sass-loader@7.1.0

Let me know if it's not working for you

