title: Access to operation 'xxx' was denied error
body: <p>We are running a Silverlight application with RIA services on an IIS 7.5, and we are just spammed with errors saying "Load operation failed for query 'xxx'. Access to operation 'xxx' was denied.". This in turn shows up in the event viewer with the information message "" (this message is currently suppressed to limit the event logging)</p>
  
  <p>The flow is: The user initially logs in and is authenticated using Forms authentication and the expiry is set 12 hours using sliding expiration. All RIA domain service class are marked with the [RequiresAuthentication].</p>
  
  <p>I'm not terribly familiar with ASP.NET and Forms authentication, but my initial thought was that the user session expired. So I made an attempt to fix it by handling DomainOperationExceptions with a status code of Unauthorized (corresponding to a 401 error) and refresh the user like so</p>
  
  <pre><code>private void OnLoadComplete(LoadResult&lt;MyObject&gt; res)
  {
      if (res.Error != null)
      {
          var dom = res.Error as DomainOperationException;
          if (dom != null &amp;&amp; dom.Status == OperationErrorStatus.Unauthorized)
          {
              WebContext.Current.HttpAuthentication.LoadUser();
          }
      }
  }
  </code></pre>
  
  <p>Unfortunately this hasn't really made any difference.</p>
  
  <p>So is it in fact a session expiry, or is there something else which might trigger this error? And what is the right way to handle it?</p>
  
  <p>Let me know what else is needed to help diagnose the problem...</p>