Module not found: Error: Can't resolve 'flag-icon-css' in - laravel

Question

I am going to install this admin panel https://coreui.io/ (free version) in my laravel project. It contains a package.json file with the following dependencies:
"dependencies": {
"#coreui/coreui": "^2.1.5",
"#coreui/coreui-plugin-chartjs-custom-tooltips": "1.2.0",
"#coreui/icons": "0.3.0",
"bootstrap": "^4.2.1",
"chart.js": "2.7.3",
"core-js": "^2.6.1",
"flag-icon-css": "^3.2.1",
"font-awesome": "4.7.0",
"jquery": "3.3.1",
"pace-progress": "1.0.2",
"perfect-scrollbar": "^1.4.0",
"popper.js": "^1.14.6",
"simple-line-icons": "2.4.1"
},
So I am just going to put these dependencies in my package.json and run
npm install and npm run dev. My project's packaje.json is
{
"private": true,
"scripts": {
"dev": "npm run development",
"development": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
"watch": "npm run development -- --watch",
"watch-poll": "npm run watch -- --watch-poll",
"hot": "cross-env NODE_ENV=development node_modules/webpack-dev-server/bin/webpack-dev-server.js --inline --hot --config=node_modules/laravel-mix/setup/webpack.config.js",
"prod": "npm run production",
"production": "cross-env NODE_ENV=production node_modules/webpack/bin/webpack.js --no-progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js"
},
"dependencies": {
"#coreui/coreui": "^2.1.6",
"#coreui/coreui-plugin-chartjs-custom-tooltips": "1.2.0",
"#coreui/icons": "0.3.0",
"bootstrap": "^4.2.1",
"chart.js": "2.7.3",
"core-js": "^2.6.1",
"flag-icon-css": "^3.2.1",
"font-awesome": "^4.7.0",
"jquery": "3.3.1",
"node-sass": "^4.11.0",
"pace": "*",
"pace-progress": "1.0.2",
"perfect-scrollbar": "^1.4.0",
"popper.js": "^1.14.6",
"simple-line-icons": "^2.4.1"
},
"devDependencies": {
"axios": "^0.18",
"bootstrap": "^4.0.0",
"cross-env": "^5.1",
"css-loader": "^2.1.0",
"jquery": "^3.2",
"laravel-mix": "^4.0.7",
"lodash": "^4.17.5",
"popper.js": "^1.12",
"resolve-url-loader": "^2.3.1",
"sass": "^1.15.2",
"sass-loader": "^7.1.0",
"style-loader": "^0.23.1",
"vue": "^2.5.17",
"vue-template-compiler": "^2.6.3"
}
}
But as result I see the following:
So, how I can fix it? What is wrong?

Answer 1

First of all ensure you have installed all packages successfully. I personally recommend you delete your node_modules then run npm install.
I think the problem is that your project doesn't found it's CSS/SASS dependencies.
Ensure to import all CSS/SASS files into your app.scss file.
For example for Simple Line Icons package you should do something like this.
#import "~simple-line-icons/scss/simple-line-icons";
Also double check all js. components
For example in your app.js
import 'coreui';