Ошибка при сборке приложения с помощью Webpack: 4, LoadConfigError: не удается найти модуль «Зигмунд»

var webpack = require('webpack');
var path = require('path');
var BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
// var OfflinePlugin = require('offline-plugin')
// const CompressionPlugin = require("compression-webpack-plugin")
const UglifyJsPlugin = require('uglifyjs-webpack-plugin')
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");

module.exports = {
  entry: {
    '/js/app': './frontend/app.js'
  },
  output: {
    filename: 'app.js',
    chunkFilename: '[name].js',
    publicPath: "/public/js/",
    path: path.resolve(__dirname, 'public', 'js')
  },
  module: {
    rules: [
      {
        test: /jquery.+\.js$/,
        use: [{
            loader: 'expose-loader',
            options: 'jQuery'
        },{
            loader: 'expose-loader',
            options: '$'
        }]
      },
      {
        test: /\.(scss|css|sass)$/i,

        use: [
          // {
          //   loader: MiniCssExtractPlugin.loader,
          //   options: {
          //     // you can specify a publicPath here
          //     // by default it use publicPath in webpackOptions.output
          //     publicPath: '../'
          //   }
          // },
          {
            loader: "style-loader"
          },
          {
            loader: "css-loader"
          },
          {
            loader: "sass-loader",
            options: {
              includePaths: [
                path.resolve("./node_modules/")
            ]
          }
        }
      ]
    },
    {
      test: /\.js$/,
      loader: "babel-loader",
      include: [
        path.resolve(__dirname, "frontend"),
      ],
      exclude: [
        path.resolve(__dirname, "node_modules")
      ],
    },
    {
      test: /\.(eot|woff|woff2|ttf|svg|png|jpg|gif)$/,
      loader: 'url-loader?limit=4096&name=[name]-[hash].[ext]'
    },
    {
      test: /\.json$/,
      loader: 'json-loader',
      type: "javascript/auto"
    }
  ]},
  node: {
    fs: "empty",
    net: "empty"
  },
  optimization: {
    minimizer: [new UglifyJsPlugin()]
  },
  performance: {
    maxEntrypointSize: 512000,
    maxAssetSize: 512000
  },
  plugins: [
    new BundleAnalyzerPlugin({
      analyzerHost: "0.0.0.0"
    }),
    new UglifyJsPlugin({
      test: /\.js(\?.*)?$/i,
      parallel: true,
      extractComments: 'all'
    }),
    new MiniCssExtractPlugin({
      filename: "[name].css",
      chunkFilename: "[id].css"
    }),
    new webpack.ProvidePlugin({
      jQuery: 'jquery',
      $: 'jquery',
      jquery: 'jquery',
      'window.jQuery': 'jquery',
      Popper: ['popper.js', 'default'],
    }),
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify('production')
    }),
    new OptimizeCSSAssetsPlugin({
      assetNameRegExp: /\.optimize\.css$/g,
      cssProcessor: require('cssnano'),
      cssProcessorPluginOptions: {
        preset: ['default', { discardComments: { removeAll: true } }],
      },
      canPrint: true
    })
    ]
    }