title: NoClassDefFoundError: org/apache/commons/collections/IteratorUtils
body: <p>I received this error:</p>
  
  <pre class="lang-none prettyprint-override"><code>NoClassDefFoundError: org/apache/commons/collections/IteratorUtils
  </code></pre>
  
  <p>I have downloaded the newest jar: <code>commons-collections4-4.0.jar</code></p>
  
  <p>And it looks like multiple libs/apps are looking for <code>commons/collections</code> (not <code>commons/collections4</code>). I am trying to use display tags and get this problem.</p>
  
  <p>Where can I find <code>commons-collections.jar</code>?</p>