title: Safari X-Frame-Options DENY error on app.facebook.com authentication process
body: <p>Safari browser only throws a X-Frame-Options DENY error for my website when iframed on Facebook during the Authentication Process</p>
  
  <p>I have taken my HTML5 PWA website an placed it within a facebook app, setting it up as a "App on Facebook".</p>
  
  <p>My website is being iframed within Facebook:  <a href="https://apps.facebook.com/bingotreasure" rel="nofollow noreferrer">https://apps.facebook.com/bingotreasure</a> and is pending approval, so it cannot be accessed publicly yet within Facebook apps.</p>
  
  <p>The first page loaded has a "Login with Facebook" button</p>
  
  <p>This Facebook authentication process in my website works without any problems on Chrome, Firefox for MS Windows as well as Chrome for Mac OS.
  However, on the same Mac Book that works with Chrome and only on Safari the following error is thrown.</p>
  
  <p>Refused to display <a href="https://facebook.com/dialog/oauth?scope=email&amp;clientid=" rel="nofollow noreferrer">https://facebook.com/dialog/oauth?scope=email&amp;clientid=</a>............'
  in a frame because it set 'X-Frame-Options' to 'DENY'.</p>
  
  <p>The fact that only Safari throws this error tells me it must be yet another problem with Safari!</p>
  
  <p>Has anyone found a solution to this error with Safari?</p>