ReactJS does not load

Hi im noob to reactJS so idk a lot about it.

I’ve just finished the Header on my project and now im working on the footer.
The thing is that if I import the Footer in index.js when page refreshes it doesn’t load.

My index.js looks like this:

import React from 'react';
import ReactDOM from 'react-dom';

//Components
import Header from './component/header/Header';
import Footer from './component/footer/Footer';

//SCSS
import './index.scss';
import './custom.scss';

const app = (

  <div>
    <Header />

    <Footer />
  </div>

);

ReactDOM.render(
  app,
  document.getElementById('root')
);

I’ve tried to update node and react, upgrade the amount of memory in the package.json but none of this works…