If you are including jQuery by using a cdn such as https://code.jquery.com/jquery-2.2.4.min.js, Laravel Mix will emit an error when compiling your scripts. First of all, you have to copy on the root of your project a fresh copy of default `webpack.config.js` (see here for more details). Next, comment the following lines:

module.exports.plugins = (module.exports.plugins || []).concat([
    new webpack.ProvidePlugin(Mix.autoload || {
        //jQuery: 'jquery',
        //$: 'jquery',
        //jquery: 'jquery',
        //'window.jQuery': 'jquery'
    }),
...