title: Outlook Web Addin manifest creates 'Invalid xsi:type=Event'
body: <p>We are creating an outlook web add-in which includes the <code>Onsend</code> feature. </p>
  
  <p>The template was working fine without adding the <code>ExtensionType</code> tag in manifest but when we added that tag, it triggers an error (<a href="https://i.imgur.com/RkfT4cf.png" rel="nofollow noreferrer">screenshot</a>):</p>
  
  <pre><code>&lt;ExtensionPoint xsi:type="Events"&gt;
    &lt;Event Type="ItemSend" FunctionExecution="synchronous" FunctionName="validateBody" /&gt;
  &lt;/ExtensionPoint&gt;
  </code></pre>
  
  <p>We <a href="https://github.com/OfficeDev/Outlook-Add-in-On-Send/issues/2" rel="nofollow noreferrer">searched further and found</a> that adding a <code>verionoverrides</code> (<a href="https://imgur.com/a/LShmu" rel="nofollow noreferrer">screenshot</a>) tag corrects the error but during compilation, it throws an error:</p>
  
  <blockquote>
    <p>Failed to deploy the manifest file to the Exchange server. An internal server error occurred. The operation failed., Object reference not set to an instance of an object.</p>
  </blockquote>
  
  <p>Does anyone confront the same error or can anyone please guide towards a right path to resolve this? </p>
  
  <p>Complete Manifest: <a href="https://files.fm/f/hca3npdt" rel="nofollow noreferrer">https://files.fm/f/hca3npdt</a></p>