title: The app ID specified within the "fb:app_id" meta tag was invalid
body: <p>I tried to enable Facebook Insights for my web. I added my page's <code>APP_ID</code> to <code>fb:admins</code> to enable every admin of my page to access Insights when logged into Facebook as Page. But when I try to save the dialog message appears:</p>
  
  <pre><code>The app ID "123,123,123,123,123" specified within the "fb:app_id" meta tag was invalid.
  </code></pre>
  
  <p>I double checked my app ID and it's correct. </p>