title: iOs : Blocked a frame with origin "https://www.youtube.com" from accessing a frame with origin
body: <p><strong>I know this question has been asked and answered a million times</strong>. But. Right now, I'm testing a website that has got some Youtube iframe embeds on iOs. It looks like :</p>
  
  <pre><code>&lt;iframe width="100%" height="200" src="//www.youtube.com/embed/my-video-id" class="yt-player-listed " frameborder="0" allowfullscreen&gt;&lt;/iframe&gt;
  </code></pre>
  
  <p>So, <strong>just the basic code provided by Youtube</strong>. It works fine on most devices. But on iOs Safari :</p>
  
  <pre><code>Blocked a frame with origin "https://www.youtube.com" from accessing a frame with origin ... from html5player.js:816
  </code></pre>
  
  <p>I don't see any protocol mismatch, as long as I'm using <code>//</code> (I also tried with http: and https:) : <strong>the iframe just doesn't appear</strong>.</p>
  
  <p>I tried : </p>
  
  <ol>
  <li>changed the protocol (http, https, //)</li>
  <li>removed all attribute in the iframe (allowfullscreen, frameborder)</li>
  </ol>
  
  <p>I don't know what's going on there...</p>