title: j {name: "ServiceWorkerQuietError", message: "Service workers can only progress forward."}
body: <p>I'm trying to use the <a href="https://developers.facebook.com/docs/messenger-platform/plugin-reference/send-to-messenger" rel="noreferrer">Send to Messenger</a> plugin, but I'm getting this error:</p>
  
  <pre><code>j {name: "ServiceWorkerQuietError", message: "Service workers can only progress forward."}
  </code></pre>
  
  <p>This is my code:</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
  &lt;script type="text/javascript" src="//connect.facebook.net/en_US/sdk.js"&gt;&lt;/script&gt;
  
  &lt;script&gt;
  
    FB.Event.subscribe('send_to_messenger', function(e) {
      // callback for events triggered by the plugin
  
    });
  &lt;/script&gt;
  
  &lt;/head&gt;
  
  
  &lt;body&gt;
  
  &lt;script&gt;
  
      window.fbAsyncInit = function() {
        FB.init({
          appId: "XXX",
          xfbml: true,
          version: "v2.6"
        });
  
      };
  
      (function(d, s, id){
         var js, fjs = d.getElementsByTagName(s)[0];
         if (d.getElementById(id)) { return; }
         js = d.createElement(s); js.id = id;
         js.src = "//connect.facebook.net/en_US/sdk.js";
         fjs.parentNode.insertBefore(js, fjs);
      }(document, 'script', 'facebook-jssdk'));
  
  &lt;/script&gt;
  
  &lt;div class="fb-send-to-messenger" 
    messenger_app_id="XXX" 
    page_id="XXX" 
    data-ref="" 
    color="blue" 
    size="large"&gt;
  &lt;/div&gt; 
  
  
  &lt;/body&gt;
  
  &lt;/html&gt;
  </code></pre>
  
  <p>How can i solve this?</p>