title: Owl carousel - TypeError: this.$element.attr(...) is undefined
body: <p>On my wordpress site i use jQuery 1.12.4 together with owl carousel 2.2. When i load an carousel i get the following error:</p>
  
  <pre><code>TypeError: this.$element.attr(...) is undefined
  </code></pre>
  
  <p>The carousel is not working. jQuery is loadad in the header and owl carousel in the footer. I call owl carousel in a js file which is loadad after the owl carousel js: </p>
  
  <pre><code>jQuery(document).ready(function($) {
      $("#services-slider").owlCarousel();
  });
  </code></pre>