A bad HTTP response code (404) was received when fetching the script - Service Worker Ionic 4

Hey !

I want to add push notification on my project. It’s working perfectly expect when the app is in background.
In order to trigger a banner notification, I added a service worker in /src (the same location than index.html.
This is the content :


  // get this from Firebase console, Cloud messaging section
  'messagingSenderId': 'MESSAGINGID'

const messaging = firebase.messaging();

messaging.setBackgroundMessageHandler(payload => {
  console.log('Received background message ', payload);
  // here you can override some options describing what's in the message; 
  // however, the actual content will come from the Webtask
  const notificationTitle = "Background message title"
  const notificationOptions = {
    body: 'Background Message body.',
    icon: '/assets/images/logo-128.png'
  return self.registration.showNotification(notificationTitle, notificationOptions);

messaging.onMessage(function(payload) {
  console.log('Message received. ', payload);

In index.html, I added this :

  /* Service worker for Firebase Cloud Messaging */
  if ('serviceWorker' in navigator) {
      .then(service => console.log('service worker installed :', service))
      .catch(err => console.error('Error', err));

I tried to remove all the content, but I’m getting the same error in console : Error TypeError: Failed to register a ServiceWorker: A bad HTTP response code (404) was received when fetching the script.

In angular.json I added foreach configurations : "serviceWorker": true,

I’m using firebase plugin : cordova-plugin-firebase@2.0.5

Do you have an idea of how I could resolve it ?

I solve it by stopping ionic serve and launch it again !
So simple …