title: Uncaught TypeError: Cannot read property 'current' of null - Select2.js on selection any option
body: <p>Select2 on dropdown always gives <code>Uncaught TypeError: Cannot read property 'current' of null</code>, when i select any data in select box it gives me error and it not call change event function</p>
  
  <blockquote>
    <p>html codes</p>
  </blockquote>
  
  <pre><code> &lt;select name="sono[]" id="sonoDetails" class="select2 form-control select2-hidden-accessible" tabindex="-1" aria-hidden="true"&gt;
      &lt;option value=""&gt;Select SO No&lt;/option&gt;
      &lt;option value="5" data-bookingtime="2015-10-16 21:00:00"&gt;5&lt;/option&gt;
      &lt;option value="4" data-bookingtime="2015-10-17 20:15:00"&gt;4&lt;/option&gt;                         
  &lt;/select&gt;
  </code></pre>
  
  <p>Js codes to get data on <code>initialize select2</code> and <code>on change</code> event handler</p>
  
  <pre><code> $(document).ready(function(){
      $(".select2").select2();
      $(document).on("change","select[name='sono[]']",function(){//
          var me = $(this);
          var sono = me.select2("val");
            console.log(sono);
      }); 
   });
  </code></pre>
  
  <p>It run fine only first time after that its always return <code>Uncaught TypeError: Cannot read property 'current' of null</code> in js...</p>
  
  <p>I want change event work for every selection but now it runs only once</p>
  
  <p>help to solve this problem</p>