title: WARNING: Could not read file on npm run build
body: <p>I am trying to deploy my React App to S3 but I get <strong>WARNING: Could not read C:/Users/*/my-app/app/actions</strong> when I build my app.</p>
  
  <p>Everything is working when I run it locally using <strong>npm start</strong>.</p>
  
  <p>These are the following things I tried but did not solve the problem:</p>
  
  <ul>
  <li>Updated the Packages</li>
  <li>Deleted the node_modules directory, cleaned cache, installed packages again</li>
  <li>Change app dir to 'app'</li>
  <li>Change publicPath to s3 instance</li>
  </ul>
  
  <p>These are my classes.</p>
  
  <p>package.json</p>
  
  <pre><code>`...
  "scripts": {
      "start": "nodemon --watch webpack.config.js --exec \"webpack-dev-server --env development\"",
      "build": "webpack --env production",
  ...`
  </code></pre>
  
  <p>webpack.config.js</p>
  
  <pre><code>`...
  const PATHS = {
    app: path.join(__dirname, 'app/'),
    style: [
      path.join(__dirname, 'app/style', 'app.css'),
    ],
    build: path.join(__dirname, 'build'),
  };
  ...
  entry: {
        app: [
          'bootstrap-loader',
          PATHS.app,
        ],
        style: PATHS.style,
      },
      output: {
        path: PATHS.build,
        publicPath: '/',
        filename: '[name].js',
      },
      resolve: {
        extensions: ['.actions.js','.component.jsx','.container.js','.reducer.js','.js', '.jsx'],
      },
  ...
  `
  </code></pre>
  
  <p>How can I successfully deploy this to S3? Any help is appreciated.</p>