title: ReferenceError: documentFragmentChildren is not defined
body: <p>I am writing a PWA Ionic 4 app to subscribe and show Firebase push notifications. Everything about it works just fine. For example, I am able to install the app in chrome browser (meaning the PWA part works well) and I can subscribe and receive messages when they are published. In my Firebase service file, I make a toast using the following function.</p>
  
  <pre><code>  async makeToast(message) {
      console.log(message);
      const toast = await this.toastController.create({
        message: message,
        duration: 5000,
        position: 'top',
        showCloseButton: true,
        closeButtonText: 'dismiss'
      });
      toast.present();
  }
  </code></pre>
  
  <p>But there is something wrong about it since I see the toast coming up but with an empty body (message). I can see in the console that the message is not empty. But there is this error</p>
  
  <pre><code> ReferenceError: documentFragmentChildren is not defined
      at r (common-es2015.edd3f5ddbecdc7d4b97d.js:1)
      at b.render (90-es2015.a511a29a06087ce2ae17.js:1)
      at pe (main-es2015.82bfa6fe443f99f03efa.js:1)
      at Array.o (main-es2015.82bfa6fe443f99f03efa.js:1)
      at D (main-es2015.82bfa6fe443f99f03efa.js:1)
      at x (main-es2015.82bfa6fe443f99f03efa.js:1)
      at a.invoke (polyfills-es2015.a5a02c8969fb7b2904df.js:1)
      at t.run (polyfills-es2015.a5a02c8969fb7b2904df.js:1)
      at polyfills-es2015.a5a02c8969fb7b2904df.js:1
      at a.invokeTask (polyfills-es2015.a5a02c8969fb7b2904df.js:1)
  r @ common-es2015.edd3f5ddbecdc7d4b97d.js:1
  </code></pre>
  
  <p>To run the code, I do</p>
  
  <pre><code>ionic build --prod
  http-server ./www -o
  </code></pre>
  
  <p>Interestingly, when I do <code>ionic serve</code> the toast works fine but PWA and Firebase breaks.</p>