React app working locally but application error when deployed to heroku

Question

I've been using Heroku from a long time and it was working fine. Now without any environment change, heroku is not working for me anymore. My app is working perfectly fine locally but when i deploy it on heroku it gives Application Error. Then i created a new app and without doing any changes i deployed this new app on heroku. It gave the exactly same error which means problem is not with my app, it's either with heroku or the way i'm deploying the app.

I use create react app and i'm adding package.json file and log file below. Please help me. I'm trying to figure it out from past two days:(

Thanks in advance for you help!

package.json

{
  "name": "react-pustepause",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.3.2",
    "@testing-library/user-event": "^7.1.2",
    "antd": "^4.0.4",
    "axios": "^0.19.2",
    "react-responsive": "^8.0.3",
    "react": "^16.13.1",
    "react-dom": "^16.13.1",
    "react-scripts": "3.4.1"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

heroku logs

2020-04-04T20:49:10.777143+00:00 app[web.1]: Starting the development server...
2020-04-04T20:49:10.777144+00:00 app[web.1]:
2020-04-04T20:49:10.847784+00:00 heroku[web.1]: State changed from starting to crashed
2020-04-04T20:49:11.613758+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=7f19caf3-ade4-4360-a31a-32b8d90cc110 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:12.382387+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=6a97a9e4-7aa1-479e-82d1-e268800693af fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:15.020120+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=c1b63c14-c058-4020-8e50-7e4db85a0616 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:15.349808+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=70152859-a3b8-48fb-af05-a6c7c77293b4 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:16.521253+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=fb1c9753-5225-476a-a168-42ec7e9f34cf fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:16.835390+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=abc45209-4f20-4171-ac93-71734680e95f fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:17.120246+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=4f4b7fd9-642a-4424-905e-d79af7a7fb38 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:17.460808+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=3a66e08a-3530-418c-a019-385506016dfc fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:17.737342+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=70d194a1-42a2-4842-ae86-1c72418629f3 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:18.045515+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=07689863-02d0-4b7f-b58a-3f04b8bb60f5 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:18.472033+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=a9ae0dfc-deb4-48e5-a4ea-ccbb25e89467 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T20:49:18.785185+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=c826cda1-cf1f-4d54-b434-215db33b4127 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-04T21:10:13.785015+00:00 heroku[web.1]: State changed from crashed to starting
2020-04-04T21:10:25.359246+00:00 app[web.1]:
2020-04-04T21:10:25.359259+00:00 app[web.1]: > react-pustepause@0.1.0 start /app
2020-04-04T21:10:25.359260+00:00 app[web.1]: > react-scripts start
2020-04-04T21:10:25.359260+00:00 app[web.1]:
2020-04-04T21:10:27.456512+00:00 app[web.1]: ℹ ｢wds｣: Project is running at http://172.18.161.114/
2020-04-04T21:10:27.456873+00:00 app[web.1]: ℹ ｢wds｣: webpack output is served from
2020-04-04T21:10:27.456958+00:00 app[web.1]: ℹ ｢wds｣: Content not from webpack is served from /app/public
2020-04-04T21:10:27.457014+00:00 app[web.1]: ℹ ｢wds｣: 404s will fallback to /
2020-04-04T21:10:27.457209+00:00 app[web.1]: Starting the development server...
2020-04-04T21:10:27.457211+00:00 app[web.1]:
2020-04-04T21:10:27.588035+00:00 heroku[web.1]: State changed from starting to crashed
2020-04-04T21:55:26.797837+00:00 heroku[web.1]: State changed from crashed to starting
2020-04-04T21:55:40.204461+00:00 app[web.1]:
2020-04-04T21:55:40.204479+00:00 app[web.1]: > react-pustepause@0.1.0 start /app
2020-04-04T21:55:40.204479+00:00 app[web.1]: > react-scripts start
2020-04-04T21:55:40.204480+00:00 app[web.1]:
2020-04-04T21:55:42.853119+00:00 app[web.1]: ℹ ｢wds｣: Project is running at http://172.18.206.246/
2020-04-04T21:55:42.853546+00:00 app[web.1]: ℹ ｢wds｣: webpack output is served from
2020-04-04T21:55:42.853636+00:00 app[web.1]: ℹ ｢wds｣: Content not from webpack is served from /app/public
2020-04-04T21:55:42.853716+00:00 app[web.1]: ℹ ｢wds｣: 404s will fallback to /
2020-04-04T21:55:42.853902+00:00 app[web.1]: Starting the development server...
2020-04-04T21:55:42.853903+00:00 app[web.1]:
2020-04-04T21:55:42.976144+00:00 heroku[web.1]: State changed from starting to crashed
2020-04-04T23:16:55.576000+00:00 heroku[web.1]: State changed from crashed to starting
2020-04-04T23:17:12.455408+00:00 app[web.1]:
2020-04-04T23:17:12.455433+00:00 app[web.1]: > react-pustepause@0.1.0 start /app
2020-04-04T23:17:12.455434+00:00 app[web.1]: > react-scripts start
2020-04-04T23:17:12.455434+00:00 app[web.1]:
2020-04-04T23:17:15.775689+00:00 app[web.1]: ℹ ｢wds｣: Project is running at http://172.16.24.26/
2020-04-04T23:17:15.776953+00:00 app[web.1]: ℹ ｢wds｣: webpack output is served from
2020-04-04T23:17:15.777103+00:00 app[web.1]: ℹ ｢wds｣: Content not from webpack is served from /app/public
2020-04-04T23:17:15.778644+00:00 app[web.1]: ℹ ｢wds｣: 404s will fallback to /
2020-04-04T23:17:15.778983+00:00 app[web.1]: Starting the development server...
2020-04-04T23:17:15.778983+00:00 app[web.1]:
2020-04-04T23:17:15.929319+00:00 heroku[web.1]: State changed from starting to crashed
2020-04-05T02:06:59.424136+00:00 heroku[web.1]: State changed from crashed to starting
2020-04-05T02:07:14.025754+00:00 app[web.1]:
2020-04-05T02:07:14.025777+00:00 app[web.1]: > react-pustepause@0.1.0 start /app
2020-04-05T02:07:14.025778+00:00 app[web.1]: > react-scripts start
2020-04-05T02:07:14.025778+00:00 app[web.1]:
2020-04-05T02:07:16.714076+00:00 app[web.1]: ℹ ｢wds｣: Project is running at http://172.17.224.6/
2020-04-05T02:07:16.714521+00:00 app[web.1]: ℹ ｢wds｣: webpack output is served from
2020-04-05T02:07:16.714621+00:00 app[web.1]: ℹ ｢wds｣: Content not from webpack is served from /app/public
2020-04-05T02:07:16.714721+00:00 app[web.1]: ℹ ｢wds｣: 404s will fallback to /
2020-04-05T02:07:16.714918+00:00 app[web.1]: Starting the development server...
2020-04-05T02:07:16.714920+00:00 app[web.1]:
2020-04-05T02:07:16.825861+00:00 heroku[web.1]: State changed from starting to crashed
2020-04-05T07:48:27.405222+00:00 heroku[web.1]: State changed from crashed to starting
2020-04-05T07:48:39.670311+00:00 app[web.1]:
2020-04-05T07:48:39.670333+00:00 app[web.1]: > react-pustepause@0.1.0 start /app
2020-04-05T07:48:39.670334+00:00 app[web.1]: > react-scripts start
2020-04-05T07:48:39.670334+00:00 app[web.1]:
2020-04-05T07:48:41.805354+00:00 app[web.1]: ℹ ｢wds｣: Project is running at http://172.16.55.206/
2020-04-05T07:48:41.805768+00:00 app[web.1]: ℹ ｢wds｣: webpack output is served from
2020-04-05T07:48:41.805879+00:00 app[web.1]: ℹ ｢wds｣: Content not from webpack is served from /app/public
2020-04-05T07:48:41.805963+00:00 app[web.1]: ℹ ｢wds｣: 404s will fallback to /
2020-04-05T07:48:41.806163+00:00 app[web.1]: Starting the development server...
2020-04-05T07:48:41.806164+00:00 app[web.1]:
2020-04-05T07:48:41.888875+00:00 heroku[web.1]: State changed from starting to crashed
2020-04-05T13:32:28.861883+00:00 heroku[web.1]: State changed from crashed to starting
2020-04-05T13:32:42.139952+00:00 app[web.1]:
2020-04-05T13:32:42.139968+00:00 app[web.1]: > react-pustepause@0.1.0 start /app
2020-04-05T13:32:42.139968+00:00 app[web.1]: > react-scripts start
2020-04-05T13:32:42.139968+00:00 app[web.1]:
2020-04-05T13:32:44.072413+00:00 app[web.1]: ℹ ｢wds｣: Project is running at http://172.16.108.126/
2020-04-05T13:32:44.072765+00:00 app[web.1]: ℹ ｢wds｣: webpack output is served from
2020-04-05T13:32:44.072839+00:00 app[web.1]: ℹ ｢wds｣: Content not from webpack is served from /app/public
2020-04-05T13:32:44.072900+00:00 app[web.1]: ℹ ｢wds｣: 404s will fallback to /
2020-04-05T13:32:44.073069+00:00 app[web.1]: Starting the development server...
2020-04-05T13:32:44.073070+00:00 app[web.1]:
2020-04-05T13:32:44.147851+00:00 heroku[web.1]: State changed from starting to crashed
2020-04-05T18:30:30.954173+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=9bbecd3c-355f-44cf-b416-fcc895e00977 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-05T18:30:32.056816+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=206fb2f9-125d-4b3b-b2b4-82350d98207f fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-05T18:38:16.519444+00:00 app[api]: Starting process with command `rake db:migrate` by user khzainulabidin@gmail.com
2020-04-05T18:38:31.243571+00:00 heroku[run.8227]: State changed from starting to up
2020-04-05T18:38:36.579921+00:00 heroku[run.8227]: State changed from up to complete
2020-04-05T18:38:43.791939+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=4576ce30-2005-4545-b84a-8847ba4e5133 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-05T18:38:44.110647+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=95628db1-c532-48e6-b9d5-6b587536c8f7 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-05T18:38:45.089377+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=5da35fd7-1d62-4acc-aed9-4ab8d53f2084 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-05T18:38:45.550772+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=7f632320-be75-4034-8702-b537e23bc38a fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-05T18:38:45.974139+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=bcf72176-4100-4a8a-80f6-4e94c6ec5b00 fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-05T18:38:46.324445+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=07824287-ee32-4870-b3db-af0e44082a2b fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-05T18:38:46.877015+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=react-pustepause.herokuapp.com request_id=41432fd5-89a2-4ab8-94de-4a90ecc48ecc fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https
2020-04-05T18:38:47.217088+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=react-pustepause.herokuapp.com request_id=a6a4826e-a3dd-4810-900e-0f1ba718f9af fwd="68.192.253.24" dyno= connect= service= status=503 bytes= protocol=https

Answer 1

So I finally found the solution. This is because of the buildpack used by Heroku. Heroku used to use 'Create React App' build pack but now it uses 'nodejs' buildpack as default, even for static react apps too. So here's the method to fix this:

If you already have deployed your app on heroku and want to fix

• Login to Heroku Web
• Go to Settings
• Under Buildpacks, click Add buildpack
• Copy and paste this url: https://buildpack-registry.s3.amazonaws.com/buildpacks/mars/create-react-app.tgz
• Click Save Changes
• Now deploy your app again (do any little changes and push the updates, don't push exactly same code as before) and new buildpack will do it's work
• Your app is ready to use!

If you haven't deployed your app or if you want to do this through command line

Use the following command to fix the issue:

heroku create $APP_NAME --buildpack mars/create-react-app
git push heroku master

Change $APP_NAME with your actual app name.

Hope that helped!