c# - Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server."

Question

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?

'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]

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.

Answer 1

This issue sometimes occurs when you have a control registered as an AsyncPostbackTrigger in multiple update panels.

If that's not the problem, try adding the following right after the script manager declaration, which I found in this post by manowar83, which copies and slightly modifies this post by larryw:

<script type="text/javascript" language="javascript">
    Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);
    function EndRequestHandler(sender, args){
        if (args.get_error() != undefined){
            args.set_errorHandled(true);
        }
    }
</script>

There are a few more solutions discussed here: http://forums.asp.net/t/1066976.aspx/9/10