title: Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server."
body: <p>I have couple of update panels and jquery tabs on page. And also I am loading couple user controls on update panels. After user waited for couple of minutes (not checked the time approx 40 mins). when user send request from submit button it is giving below error? </p>
  
  <pre><code>'Sys.WebForms.PageRequestManagerServerErrorException:
  Sys.WebForms.PageRequestManagerServerErrorException: An unknown 
  error occurred while processing the request on the server. The status 
  code returned from the server was: 0' when calling method: 
  [nsIDOMEventListener::handleEvent]
  </code></pre>
  
  <p>I am not able trace this issue to fix. But I am sure. This is causing by Ajax. Gurus, if you knows solution. Please let me know.</p>