title: Type "myadtype" is not supported in amp-ad
body: <p>I'm using an <code>&lt;amp-ad&gt;</code> tag to serve ads to a site. I'm using the <code>remote.html</code> file to specify a custom ad type. It worked like charm for month. Now, about 2 weeks ago, it just stopped working. Nothing changed on our side. It fails even on a blank site. The error is:</p>
  
  <blockquote>
    <p>Type "myadtype" is not supported in amp-ad.</p>
  </blockquote>
  
  <p>I was searching for any changes in the AMP template but could not find any.
  What the hell could cause the problem?</p>