Router only have one child component error - reactjs

Question

I want to create a page in such a way that it will route in such a way....... that
App.js to HomePage.js to Footer.js. Now when I try to perform this task it shows error that Router has only 1 child element.
Code for App.js:
import React, { Component } from 'react';
import logo from './logo.svg';
import HomePage from './Home_page'
import './App.css';
class App extends Component {
render() {
return (
<div className="App">
<header className="App-header">
<img src={logo} className="App-logo" alt="logo" />
<h1 className="App-title">Welcome to React</h1>
</header>
<p className="App-intro">
To get started, edit <code>src/App.js</code> and save to reload.
</p>
<HomePage />
</div>
);
}
}
export default App;
Code for Home_page.js
import React, {Component} from 'react';
import { BrowserRouter as Router, Switch, Route, Link } from 'react-router-dom';
import FooterPage from './FooterPage';
class HomePage extends Component {
render(){
return(
<Router>
<div>
<Link to='./FooterPage'>Footer Page</Link>
</div>
<Switch>
<Route exact path='./FooterPage' component={FooterPage} />
</Switch>
</Router>
);
}
}
export default HomePage;
Code for Footer.js
import React, {Component} from 'react';
import { BrowserRouter as Router, Switch, Route, Link } from 'react-router-dom';
class FooterPage extends Component {
render(){
return(
<div>
</div>
);
}
}
export default FooterPage;

Answer 1

At your Home_Page.js
import React, {Component} from 'react';
import { BrowserRouter as Router, Switch, Route, Link } from 'react-router-dom';
import FooterPage from './FooterPage';
class HomePage extends Component {
render(){
return(
<Router>
<div>
<div>
<Link to='./FooterPage'>Footer Page</Link>
</div>
<Switch>
<Route exact path='./FooterPage' component={FooterPage} />
</Switch>
</div>
</Router>
);
}
}
export default HomePage;
here you have only one child inside Route, not two. See https://github.com/ReactTraining/react-router/blob/master/packages/react-router-dom/docs/api/BrowserRouter.md