title: Event Receiver for Document Library
body: <p>I'm trying to update one of the properties of a word document from an event receiver.</p>
  
  <p>I'm handling it with the <strong><em>ItemAdded</em></strong> event and updating the property as is:</p>
  
  <pre><code>// Modify property
  DisableEventFiring();
  properties.ListItem.File.CheckOut();
  properties.AfterProperties[HelloWorldInternalFieldName] = "Hello World!";
  properties.ListItem.UpdateOverwriteVersion();
  properties.ListItem.File.CheckIn("Updating Property!");
  properties.ListItem.SystemUpdate();
  EnableEventFiring();
  </code></pre>
  
  <p>I'm getting an exception when I'm trying to modify it and it is saying:</p>
  
  <blockquote>
    <p>The event does not support change of
    properties.</p>
  </blockquote>
  
  <p>Does anyone have an idea why and why I cannot update the property after I save the document to the document library in Word?</p>
  
  <p>Thanks!</p>