title: Heroku[router]: at=error code=H10 desc=”App crashed“ method=GET path=/favicon.ico”
body: <p>I have a simple MERN APP, that works fine on localhost, but when I deploy it to Heroku I see a page with this error:</p>
  <blockquote>
  <p>Application error An error occurred in the application and your page
  could not be served. If you are the application owner, check your logs
  for details. You can do this from the Heroku CLI with the command
  <code>heroku logs --tail</code></p>
  </blockquote>
  <p>And the console is showing this: <code>Failed to load resource: the server responded with a status of 503 (Service Unavailable)</code></p>
  <p><a href="https://i.stack.imgur.com/NmyRr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NmyRr.png" alt="enter image description here" /></a></p>
  <p>An Image of that has also been attached!</p>
  <p>And Heroku logs are also given below...</p>
  <p>I'm new to MERN Dev, so can't really figure out what's the issue really is and Heroku logs are also not much of help, please help me!</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>Warning: heroku update available from 7.59.0 to 7.59.2.
  2022-01-05T13:28:24.783142+00:00 app[web.1]: 
  2022-01-05T13:28:25.124488+00:00 app[web.1]: /app/node_modules/whatwg-url/lib/encoding.js:2
  2022-01-05T13:28:25.124505+00:00 app[web.1]: const utf8Encoder = new TextEncoder();
  2022-01-05T13:28:25.124505+00:00 app[web.1]: ^
  2022-01-05T13:28:25.124506+00:00 app[web.1]:
  2022-01-05T13:28:25.124507+00:00 app[web.1]: ReferenceError: TextEncoder is not defined
  2022-01-05T13:28:25.124507+00:00 app[web.1]: at Object.&lt;anonymous&gt; (/app/node_modules/whatwg-url/lib/encoding.js:2:21)
  2022-01-05T13:28:25.124508+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:776:30)
  2022-01-05T13:28:25.124508+00:00 app[web.1]: at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
  2022-01-05T13:28:25.124509+00:00 app[web.1]: at Module.load (internal/modules/cjs/loader.js:653:32)
  2022-01-05T13:28:25.124509+00:00 app[web.1]: at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
  2022-01-05T13:28:25.124509+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:585:3)
  2022-01-05T13:28:25.124509+00:00 app[web.1]: at Module.require (internal/modules/cjs/loader.js:690:17)
  2022-01-05T13:28:25.124510+00:00 app[web.1]: at require (internal/modules/cjs/helpers.js:25:18)
  2022-01-05T13:28:25.124511+00:00 app[web.1]: at Object.&lt;anonymous&gt; (/app/node_modules/whatwg-url/lib/url-state-machine.js:5:34)        
  2022-01-05T13:28:25.124511+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:776:30)
  2022-01-05T13:28:25.129285+00:00 app[web.1]: npm ERR! code ELIFECYCLE
  2022-01-05T13:28:25.129543+00:00 app[web.1]: npm ERR! errno 1
  2022-01-05T13:28:25.130631+00:00 app[web.1]: npm ERR! server@1.0.0 start: `node server.js`
  2022-01-05T13:28:25.130632+00:00 app[web.1]: npm ERR! Exit status 1
  2022-01-05T13:28:25.130787+00:00 app[web.1]: npm ERR!
  2022-01-05T13:28:25.130867+00:00 app[web.1]: npm ERR! Failed at the server@1.0.0 start script.
  2022-01-05T13:28:25.130870+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
  2022-01-05T13:28:25.135681+00:00 app[web.1]:
  2022-01-05T13:28:25.135782+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
  2022-01-05T13:28:25.135828+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-01-05T13_28_25_131Z-debug.log
  2022-01-05T13:28:25.273876+00:00 heroku[web.1]: Process exited with status 1
  2022-01-05T13:28:25.334794+00:00 heroku[web.1]: State changed from starting to crashed
  2022-01-05T14:58:18.000000+00:00 app[api]: Build started by user sauviksood@gmail.com
  2022-01-05T14:59:12.408461+00:00 app[api]: Deploy 278ece53 by user sauviksood@gmail.com
  2022-01-05T14:59:12.408461+00:00 app[api]: Release v6 created by user sauviksood@gmail.com
  2022-01-05T14:59:13.000000+00:00 app[api]: Build succeeded
  2022-01-05T14:59:13.762177+00:00 heroku[web.1]: State changed from crashed to starting
  2022-01-05T14:59:19.381206+00:00 heroku[web.1]: Starting process with command `npm start`
  2022-01-05T14:59:21.141420+00:00 app[web.1]: 
  2022-01-05T14:59:21.141434+00:00 app[web.1]: &gt; server@1.0.0 start /app
  2022-01-05T14:59:21.141435+00:00 app[web.1]: &gt; node server.js
  2022-01-05T14:59:21.141435+00:00 app[web.1]:
  2022-01-05T14:59:21.365509+00:00 app[web.1]: /app/node_modules/whatwg-url/lib/encoding.js:2
  2022-01-05T14:59:21.365511+00:00 app[web.1]: const utf8Encoder = new TextEncoder();
  2022-01-05T14:59:21.365511+00:00 app[web.1]: ^
  2022-01-05T14:59:21.365512+00:00 app[web.1]:
  2022-01-05T14:59:21.365512+00:00 app[web.1]: ReferenceError: TextEncoder is not defined
  2022-01-05T14:59:21.365512+00:00 app[web.1]: at Object.&lt;anonymous&gt; (/app/node_modules/whatwg-url/lib/encoding.js:2:21)
  2022-01-05T14:59:21.365513+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:776:30)
  2022-01-05T14:59:21.365513+00:00 app[web.1]: at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
  2022-01-05T14:59:21.365514+00:00 app[web.1]: at Module.load (internal/modules/cjs/loader.js:653:32)
  2022-01-05T14:59:21.365514+00:00 app[web.1]: at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
  2022-01-05T14:59:21.365514+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:585:3)
  2022-01-05T14:59:21.365514+00:00 app[web.1]: at Module.require (internal/modules/cjs/loader.js:690:17)
  2022-01-05T14:59:21.365515+00:00 app[web.1]: at require (internal/modules/cjs/helpers.js:25:18)
  2022-01-05T14:59:21.365516+00:00 app[web.1]: at Object.&lt;anonymous&gt; (/app/node_modules/whatwg-url/lib/url-state-machine.js:5:34)
  2022-01-05T14:59:21.365518+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:776:30)
  2022-01-05T14:59:21.370906+00:00 app[web.1]: npm ERR! code ELIFECYCLE
  2022-01-05T14:59:21.371167+00:00 app[web.1]: npm ERR! errno 1
  2022-01-05T14:59:21.371985+00:00 app[web.1]: npm ERR! server@1.0.0 start: `node server.js`
  2022-01-05T14:59:21.372041+00:00 app[web.1]: npm ERR! Exit status 1
  2022-01-05T14:59:21.372158+00:00 app[web.1]: npm ERR!
  2022-01-05T14:59:21.372219+00:00 app[web.1]: npm ERR! Failed at the server@1.0.0 start script.
  2022-01-05T14:59:21.372273+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
  2022-01-05T14:59:21.375303+00:00 app[web.1]: 
  2022-01-05T14:59:21.375391+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
  2022-01-05T14:59:21.375436+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-01-05T14_59_21_373Z-debug.log
  2022-01-05T14:59:21.529167+00:00 heroku[web.1]: Process exited with status 1
  2022-01-05T14:59:21.611061+00:00 heroku[web.1]: State changed from starting to crashed
  2022-01-05T14:59:21.635160+00:00 heroku[web.1]: State changed from crashed to starting
  2022-01-05T14:59:28.249204+00:00 heroku[web.1]: Starting process with command `npm start`
  2022-01-05T14:59:29.604172+00:00 app[web.1]:
  2022-01-05T14:59:29.604192+00:00 app[web.1]: &gt; server@1.0.0 start /app
  2022-01-05T14:59:29.604193+00:00 app[web.1]: &gt; node server.js
  2022-01-05T14:59:29.604193+00:00 app[web.1]: 
  2022-01-05T14:59:29.864349+00:00 app[web.1]: /app/node_modules/whatwg-url/lib/encoding.js:2
  2022-01-05T14:59:29.864368+00:00 app[web.1]: const utf8Encoder = new TextEncoder();
  2022-01-05T14:59:29.864369+00:00 app[web.1]: ^
  2022-01-05T14:59:29.864369+00:00 app[web.1]:
  2022-01-05T14:59:29.864370+00:00 app[web.1]: ReferenceError: TextEncoder is not defined
  2022-01-05T14:59:29.864370+00:00 app[web.1]: at Object.&lt;anonymous&gt; (/app/node_modules/whatwg-url/lib/encoding.js:2:21)
  2022-01-05T14:59:29.864370+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:776:30)
  2022-01-05T14:59:29.864371+00:00 app[web.1]: at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
  2022-01-05T14:59:29.864371+00:00 app[web.1]: at Module.load (internal/modules/cjs/loader.js:653:32)
  2022-01-05T14:59:29.864371+00:00 app[web.1]: at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
  2022-01-05T14:59:29.864371+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:585:3)
  2022-01-05T14:59:29.864372+00:00 app[web.1]: at Module.require (internal/modules/cjs/loader.js:690:17)
  2022-01-05T14:59:29.864372+00:00 app[web.1]: at require (internal/modules/cjs/helpers.js:25:18)
  2022-01-05T14:59:29.864373+00:00 app[web.1]: at Object.&lt;anonymous&gt; (/app/node_modules/whatwg-url/lib/url-state-machine.js:5:34)        
  2022-01-05T14:59:29.864373+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:776:30)
  2022-01-05T14:59:29.870542+00:00 app[web.1]: npm ERR! code ELIFECYCLE
  2022-01-05T14:59:29.870848+00:00 app[web.1]: npm ERR! errno 1
  2022-01-05T14:59:29.871728+00:00 app[web.1]: npm ERR! server@1.0.0 start: `node server.js`
  2022-01-05T14:59:29.871798+00:00 app[web.1]: npm ERR! Exit status 1
  2022-01-05T14:59:29.871921+00:00 app[web.1]: npm ERR!
  2022-01-05T14:59:29.871982+00:00 app[web.1]: npm ERR! Failed at the server@1.0.0 start script.
  2022-01-05T14:59:29.872035+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
  2022-01-05T14:59:29.875332+00:00 app[web.1]:
  2022-01-05T14:59:29.875429+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
  2022-01-05T14:59:29.875474+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2022-01-05T14_59_29_872Z-debug.log
  2022-01-05T14:59:30.008365+00:00 heroku[web.1]: Process exited with status 1
  2022-01-05T14:59:30.061904+00:00 heroku[web.1]: State changed from starting to crashed
  2022-01-05T14:59:31.128259+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=movie-watchlist-mern.herokuapp.com request_id=f86c07e6-1ee6-42c9-88be-3c7d1a60e53d fwd="103.155.240.47" dyno= connect= service= status=503 bytes= protocol=https
  2022-01-05T14:59:34.147698+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=movie-watchlist-mern.herokuapp.com request_id=c0ccd4db-98b3-40fa-90c1-ad33cfe5a065 fwd="103.155.240.47" dyno= connect= service= status=503 bytes= protocol=https</code></pre>
  </div>
  </div>
  </p>