希望有人能帮助我，因为我在我的智慧结束试图找出为什么这是没有加载。网站编译没有错误，但然后只是挂起加载和白屏; DOM中也没有任何内容可以指出错误所在。
下面是源代码（https://github.com/Asutherland8219/react-portfolio）
Index.js

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';

ReactDOM.render(
    <App />
 , document.getElementById('root')
);

App.js

import React from 'react'
import './App.css';
import Navbar from './components/Navbar/Navbar';
import {BrowserRouter as Router, Switch, Route} from 'react-router-dom'
import Home from './pages/Home';
import About from './pages/About';
import Portfolio from './pages/Portfolio';
import Contact from './pages/Contact';

function App() {
  return (
      <Router>
        <Navbar />
        <Switch>
          <Route path='/' exact component= {Home}/>
          <Route path='/about' component= {About}/>
          <Route path='/portfolio' component= {Portfolio}/>
          <Route path='/contact' component= {Contact}/>
        </Switch>
      </Router>
   
    );
  }

export default App;