title: React app runs locally but crashes on Heroku
body: <p>I've spent 6+ hours trying to figure out why this won't run successfully on Heroku. It runs locally but when I deploy to Heroku I get the following log basically just saying the app crashed. I installed Heroku's CLI and tried to find a more helpful error in that but to no avail. Anyone else have any ideas or suggestions? </p>
  
  <p>Code => <a href="https://github.com/ghughes13/react-todo-list" rel="nofollow noreferrer">https://github.com/ghughes13/react-todo-list</a></p>
  
  <p><a href="https://ghughes-react-todo-list.herokuapp.com/" rel="nofollow noreferrer">https://ghughes-react-todo-list.herokuapp.com/</a></p>
  
  <pre><code>2020-04-05T14:46:31.351885+00:00 app[web.1]: [34mℹ[39m [90m｢wds｣[39m: Project is running at http://172.18.176.170/
  2020-04-05T14:46:31.355002+00:00 app[web.1]: [34mℹ[39m [90m｢wds｣[39m: webpack output is served from 
  2020-04-05T14:46:31.355159+00:00 app[web.1]: [34mℹ[39m [90m｢wds｣[39m: Content not from webpack is served from /app/public
  2020-04-05T14:46:31.355252+00:00 app[web.1]: [34mℹ[39m [90m｢wds｣[39m: 404s will fallback to /
  2020-04-05T14:46:31.355468+00:00 app[web.1]: Starting the development server...
  2020-04-05T14:46:31.355470+00:00 app[web.1]: 
  2020-04-05T14:46:31.498661+00:00 heroku[web.1]: State changed from starting to crashed
  2020-04-05T14:46:33.839876+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=ghughes-react-todo-list.herokuapp.com request_id=199836cb-d38a-4941-aee7-fc5e5deba5dc fwd="97.99.41.155" dyno= connect= service= status=503 bytes= protocol=https
  2020-04-05T14:46:34.454912+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=ghughes-react-todo-list.herokuapp.com request_id=b905fff4-83bf-4319-801a-c2c4f1d7a4e1 fwd="97.99.41.155" dyno= connect= service= status=503 bytes= protocol=https
  </code></pre>
  
  <pre><code>  "name": "todo-list",
    "version": "0.1.0",
    "private": true,
    "dependencies": {
      "@reach/router": "^1.3.3",
      "axios": "^0.19.2",
      "mongodb": "^3.5.2",
      "mongodb-client-encryption": "^1.0.1",
      "mongoose": "^5.8.11",
      "reach": "^1.0.1",
      "react": "^16.9.0",
      "react-dom": "^16.9.0",
      "react-scripts": "^3.4.1"
    },
    "scripts": {
      "start": "react-scripts start",
      "build": "react-scripts build",
      "test": "react-scripts test",
      "eject": "react-scripts eject"
    },
    "eslintConfig": {
      "extends": "react-app"
    },
    "browserslist": {
      "production": [
        "&gt;0.2%",
        "not dead",
        "not op_mini all"
      ],
      "development": [
        "last 1 chrome version",
        "last 1 firefox version",
        "last 1 safari version"
      ]
    }
  }
  </code></pre>