title: Object doesn't support property or method 'entries' - error in IE11
body: <p>I am working on a react app bootstrapped using create-react-app and it works perfectly in Chrome but I cannot get it to work in IE11.</p>
  
  <p>Upon launching the app, I am getting the following error from the console:</p>
  
  <p><code>Object doesn't support property or method 'entries'</code></p>
  
  <p>I have spent hours trawling Google trying to find a solution and none of the recommended ones work. </p>
  
  <p><strong>Things I have tried:</strong></p>
  
  <ul>
  <li>importing <code>react-app-polyfill/ie11</code> and <code>react-app-polyfill/stable</code> at the top of <code>index.js</code></li>
  <li>importing <code>core-js/es/object/entries</code> and <code>core-js/features/object/entries</code> at the top of <code>index.js</code></li>
  <li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries#Polyfill" rel="nofollow noreferrer">Adding the following to <code>index.js</code></a>:</li>
  </ul>
  
  <pre class="lang-js prettyprint-override"><code>if (!Object.entries) {
    Object.entries = function( obj ){
      var ownProps = Object.keys( obj ),
          i = ownProps.length,
          resArray = new Array(i); // preallocate the Array
      while (i--)
        resArray[i] = [ownProps[i], obj[ownProps[i]]];
  
      return resArray;
    };
  }
  </code></pre>
  
  <p><strong>package.json:</strong></p>
  
  <pre class="lang-js prettyprint-override"><code>{
    "name": "ceas-ui",
    "version": "0.1.0",
    "private": true,
    "dependencies": {
      "auth0-js": "^9.8.2",
      "bootstrap": "^4.1.3",
      "core-js": "^3.6.4",
      "env-cmd": "^8.0.2",
      "joi-browser": "^13.4.0",
      "react": "^16.12.0",
      "react-app-polyfill": "^1.0.6",
      "react-bootstrap": "^1.0.0-beta.16",
      "react-dom": "^16.12.0",
      "react-loader-spinner": "^2.3.0",
      "react-modal": "^3.8.1",
      "react-router-bootstrap": "^0.25.0",
      "react-router-dom": "^5.1.2",
      "react-scripts": "^3.3.1",
      "react-slidedown": "^2.4.5",
      "react-toastify": "^4.5.2",
      "styled-components": "^5.0.0"
    },
    "scripts": {
      "start": "react-scripts start",
      "test": "cls &amp;&amp; react-scripts test --coverage --env=jsdom",
      "eject": "react-scripts eject"
    },
    "eslintConfig": {
      "extends": "react-app"
    },
    "browser": {
      "joi": "joi-browser"
    },
    "devDependencies": {
      "babel-cli": "^6.26.0",
      "babel-core": "^6.26.3",
      "babel-plugin-transform-class-properties": "^6.24.1",
      "babel-preset-es2015": "^6.24.1",
      "babel-preset-react": "^6.24.1",
      "babel-preset-stage-0": "^6.24.1",
      "chai": "^4.2.0",
      "enzyme": "^3.9.0",
      "enzyme-adapter-react-16": "^1.9.0",
      "jsdom": "^13.2.0",
      "mocha": "^6.0.0",
      "react-test-renderer": "^16.8.2",
      "rimraf": "^2.6.3"
    },
    "browserslist": {
      "production": [
        "&gt;0.2%",
        "not dead",
        "not op_mini all",
        "ie 11"
      ],
      "development": [
        "&gt;0.2%",
        "not dead",
        "not op_mini all",
        "last 1 chrome version",
        "last 1 firefox version",
        "last 1 safari version",
        "ie 11"
      ]
    }
  }
  </code></pre>
  
  <p><strong>References:</strong></p>
  
  <ul>
  <li><a href="https://github.com/facebook/create-react-app/issues/8405" rel="nofollow noreferrer">https://github.com/facebook/create-react-app/issues/8405</a></li>
  <li><a href="https://stackoverflow.com/questions/43756211/best-way-to-polyfill-es6-features-in-react-app-that-uses-create-react-app">Best way to polyfill ES6 features in React app that uses create-react-app</a></li>
  </ul>