title: Error when i go into production with react.js
body: <p>I have create an app with react.js. I wanted to go into production.</p>
  
  <p>I did </p>
  
  <pre><code>npm run build
  
  serve -s build 
  </code></pre>
  
  <p>I go on <code>localhost:5000</code></p>
  
  <p>The welcome page works very well, but when i go on <code>localhost:5000/main</code>i have an error</p>
  
  <pre><code>404 | The requested path could not be found
  </code></pre>
  
  <p>I tried to redo <code>npm run build</code>, but that did not work</p>
  
  <p>What do you propose ?</p>
  
  <p>EDIT </p>
  
  <p>Package.json</p>
  
  <pre><code>{
    "name": "name-app",
    "version": "0.1.0",
    "private": true,
    "dependencies": {
      "firebase": "^5.10.0",
      "node-sass": "^4.11.0",
      "p5": "^0.8.0",
      "react": "^16.8.6",
      "react-dom": "^16.8.6",
      "react-p5-wrapper": "0.0.4",
      "react-router-dom": "^5.0.0",
      "react-scripts": "2.1.8",
      "socket.io-client": "^2.2.0"
    },
    "scripts": {
      "start": "react-scripts start",
      "build": "react-scripts build",
      "test": "react-scripts test",
      "eject": "react-scripts eject"
    },
    "eslintConfig": {
      "extends": "react-app"
    },
    "browserslist": [
      "&gt;0.2%",
      "not dead",
      "not ie &lt;= 11",
      "not op_mini all"
    ],
    "description": "This project was bootstrapped with [Create React App](https://github.com/facebook/create-react-app).",
    "main": "index.js",
    "devDependencies": {},
    "author": "",
    "license": "ISC"
  }
  </code></pre>