Contextual gadgets are not loading on sender account in Gmail

Question

We are trying to test contextual gadget Hello World as given on https://developers.google.com/gmail/contextual_gadgets. But we are facing problem in loading gadget. We have loaded gadget in gmail before 4 days and after that it is deleted now. But yesterday we have added new gadget but with different name, but still old gadget is loading in gmail. So, how should we know which gadget XML path is loaded in gmail?

<!-- This one is not specific to Gmail contextual gadgets. -->
<Require feature="dynamic-height"/>
   <!-- The next feature, google.contentmatch, is required for all
 Gmail contextual gadgets.
 <Param> - specify one or more comma-separated extractor IDs in
 a param named "extractors". This line is overridden by the extractor ID
 in the manifest, but is still expected to be present. -->
<Require feature="google.contentmatch">
  <Param name="extractors">
    google.com:HelloWorld,google.com:SenderEmailExtractor
    </Param>
   </Require>
 </ModulePrefs>

<!-- Define the content type and display location. The settings
"html" and "card" are required for all Gmail contextual gadgets. -->
<Content type="html" view="card">
<![CDATA[
  <!-- Start with Single Sign-On -->
  <script type="text/javascript" src="https://example.com/gadgets/sso.js"></script>
  <script type="text/javascript">
    alert("google");
    <!-- Fetch the array of content matches. -->
    matches = google.contentmatch.getContentMatches();
    var matchList = document.createElement('UL');
    var listItem;
    var extractedText;
    <!-- Iterate through the array and display output for each match. -->
    for (var match in matches) {
      for (var key in matches[match]) {
        listItem = document.createElement('LI');

        extractedText = document.createTextNode( ": dm" );
        extractedText = document.createTextNode(key + ": " + matches[match][key]);
        listItem.appendChild(extractedText);
        matchList.appendChild(listItem);
      }
    }
    document.body.appendChild(matchList);
    gadgets.window.adjustHeight(100);
      </script>
    ]]>
 </Content>

Even if gadget is deleted in account but still gadget get loaded in email. We have tried &nogadgetcache=1 in address bar but it doesn't work after again signing in to gmail account.