title: Outlook add-in is showing an empty html content upon first load
body: <p>I am currently building an office 365 <code>add-in</code> on outlook and upon first load the add in is showing an empty html content like so before the whole add in render correctly after couple of seconds</p>
  <pre><code>&lt;html&gt;
   &lt;head&gt;&lt;/head&gt;
   &lt;body&gt;&lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  <p>First I thought it is from the <code>office.then</code> function shown below and I tried to add a spinner before the <code>.then</code> is called but the loader didn't show, and I couldn't find the reason behind this.</p>
  <p>Note that the add-in is developed with react and the following is the <code>index.js</code> page
  Also note that the blank page is only showing on <code>outlook for windows</code> installed on a window 10 machine</p>
  <pre><code>import &quot;office-ui-fabric-react/dist/css/fabric.min.css&quot;;
  import App from &quot;./components/App&quot;;
  import { AppContainer } from &quot;react-hot-loader&quot;;
  import { initializeIcons } from &quot;@fluentui/react/lib/Icons&quot;;
  import * as React from &quot;react&quot;;
  import * as ReactDOM from &quot;react-dom&quot;;
  import { Provider } from &quot;react-redux&quot;;
  import store from &quot;../../store/store&quot;;
  import 'react-app-polyfill/ie11';
  import Spinner from '@atlaskit/spinner';
  
  /* global AppCpntainer, Component, document, Office, module, React, require */
  initializeIcons();
  
  let isOfficeInitialized = false;
  const title = &quot;test&quot;;
  
  const render = Component =&gt; {
  
  ReactDOM.render(
    &lt;Provider store={store}&gt;
      &lt;AppContainer&gt;
        &lt;Component title={title} isOfficeInitialized={isOfficeInitialized} /&gt;
     &lt;/AppContainer&gt;
   &lt;/Provider&gt;,
   document.getElementById(&quot;container&quot;)
    );
  };
  
  Office.onReady().then(function () {
   isOfficeInitialized = true;
    render(App);
  });
  render(App);
  
  if (module.hot) {
   module.hot.accept(&quot;./components/App&quot;, () =&gt; {
     const NextApp = require(&quot;./components/App&quot;).default;
     render(NextApp);
    });
   }
  </code></pre>
  <p><a href="https://i.stack.imgur.com/DxAfR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DxAfR.png" alt="enter image description here" /></a></p>