title: Symfony 4 and MercureBundle
body: <p>I'm a new user of this platform and I'm trying to integrate Mercure into Symfony by following the documentation: <a href="https://symfony.com/blog/symfony-gets-real-time-push-capabilities" rel="nofollow noreferrer">https://symfony.com/blog/symfony-gets-real-time-push-capabilities</a> . Once all the steps in the console are followed of chrome to the response of the Publisher class an error is generated:</p>
  
  <blockquote>
    <p>net :: ERR_ABORTED 406.</p>
  </blockquote>
  
  <p>Could you help me to understand how to make this bundle work? </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-html lang-html prettyprint-override"><code>namespace App\Controller;
  
  use Symfony\Component\HttpFoundation\Response;
  use Symfony\Component\Mercure\Publisher;
  use Symfony\Component\Mercure\Update;
  
  class PublishController
  {
      public function __invoke(Publisher $publisher)
      {
          $update = new Update(
              'http://example.com/books/1',
              json_encode(['status' =&gt; 'OutOfStock'])
          );
  
  
          // The Publisher service is an invokable object
          $publisher($update);
      }
  }</code></pre>
  </div>
  </div>
  </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-html lang-html prettyprint-override"><code>const es = new EventSource('https://www.davidecpr.online/hub?topic=' + encodeURIComponent('http://example.com/books/1'));
              es.onmessage = e =&gt; {
                  // Will be called every time an update is published by the server
                  console.log(JSON.parse(e.data));
              };</code></pre>
  </div>
  </div>
  </p>
  
  <p>The .env variable is set like this: 
  'MERCURE_PUBLISH_URL' => '<a href="http://www.davidecpr.online:3000/hub" rel="nofollow noreferrer">http://www.davidecpr.online:3000/hub</a>'</p>