Content Preview UI Element doesn't display file content in ReactJS created with create-react-app

I create a reactjs project with npx create-react-app my-app.  I've install the necessary packages and dependencies:

1. npx create-react-app my-app
2. navigate to my-app folder 
3. npm install box-ui-elements
4. npm install node-sass axios classnames draft-js form-serialize jsuri pikaday react-animate-height react-intl@2.8.0 react-measure react-process-string react-router-dom react-tether react-textarea-autosize scroll-into-view-if-needed tabbable 

I created a new Components folder containing a file called DocViewer.js with this content:

import ContentPreview from 'box-ui-elements/es/elements/content-preview';

import messages from 'box-ui-elements/i18n/en-US';

const FILE_ID_DOC = '999999';
const token = 'my_dev_token';
const language = 'en-US';

function DocViewer(props) {
    return (
        
    );
}
export default DocViewer;

My index.js file contains this:

import React from 'react';
import { render } from 'react-dom';
import './index.css';
import DocViewer from './Components/DocViewer';

import * as serviceWorker from './serviceWorker';

const container = document.querySelector('.container');
render (
, container
);

serviceWorker.unregister();

And my public/index.html contains this:

  
    
    
    
    
    
    
    
    React App
  
  
    
    

  

My reactJS project transpiled just fine without any errors.  The browser came up and loaded the page. Since I turned on the header I can see the filename displayed with icon buttons showing up. HOWEVER, the content of the file would not display.  I check the dev tools and no errors at all.  The file did load because I can see the network status loaded the file.  I can confirm the file stream was sent to the browser because when I click the download icon in the Preview the PDF file downloaded and opened successfully.

I have attached a screenshot, as you can see it's doesn't paint/display the content of the file but the stream was received by the browser. This file does open in Box.com.