title: Prototype API not work in WSO2 API manger 1.9
body: <p>I have created a prototype API in WSO2 API manager 1.9. But i am  getting following error while accessing the API</p>
  
  <pre><code>&lt;am:fault xmlns:am="http://wso2.org/apimanager"&gt;
  &lt;am:code&gt;0&lt;/am:code&gt;
  &lt;am:type&gt;Status report&lt;/am:type&gt;
  &lt;am:message&gt;Runtime Error&lt;/am:message&gt;
  &lt;am:description&gt;
  Error occured in the mediation of the class mediator
  &lt;/am:description&gt;
  &lt;/am:fault&gt;
  </code></pre>
  
  <p>What is the reason ,Any suggestion?</p>