Comments on: Updated your web.config, but Sys is still undefined?

By: vaishali

vaishali — Thu, 04 Mar 2010 04:38:28 +0000

Thanks, the error is resolved.

By: Silvia Terzi

Silvia Terzi — Tue, 16 Feb 2010 15:40:28 +0000

Help, I have the same problem and I also use Telerik. Have you solved the problem? How did you solved it?

By: Sunny Chevli

Sunny Chevli — Mon, 21 Dec 2009 10:21:55 +0000

I am looking for same solution. I am getting ’sys is not defined’ error

any solution?

By: bibhu

bibhu — Fri, 23 Oct 2009 06:30:13 +0000

Thanks a ton

By: gemini twin

gemini twin — Tue, 06 Oct 2009 10:32:42 +0000

try using an ajax enabled website instead
it worked for me

By: Kushal

Kushal — Mon, 05 Oct 2009 07:04:12 +0000

Keep up the great work!!
thanks a lot

By: Dave Ward

Dave Ward — Wed, 16 Sep 2009 19:09:07 +0000

Check your web.config for . It is automatically added during the 1.x upgrade process and breaks ASP.NET AJAX: http://weblogs.asp.net/scottgu/archive/2006/12/10/gotcha-don-t-use-xhtmlconformance-mode-legacy-with-asp-net-ajax.aspx

By: Josh Korn

Josh Korn — Wed, 16 Sep 2009 19:06:51 +0000

This problem turns out to have its roots in a legacy page (where legacy means “first built with .NET 1.1″). When the markup and code are copied into a freshly built ASP.NET Ajax web form, the right thing happens.

It’s not clear to me exactly what the problem is, although one possible culprit is that new pages have while old pages have just a element.

Cheers
Josh

By: Josh Korn

Josh Korn — Mon, 14 Sep 2009 17:47:11 +0000

Hmmm … I followed this to a T, but still get the same problem — Sys.WebForms is undefined. Sys.Application is fine, but not Sys.WebForms.

What else could be wrong?

Thx
Josh

By: Shamshad Khan

Shamshad Khan — Thu, 23 Jul 2009 09:47:16 +0000

Thanks a lot for your help

By: Rahul

Rahul — Wed, 08 Apr 2009 12:24:38 +0000

Hi Dave,

Nice article. I too get this error (in production….dead duck i am). But it is inconsistent. I have all modules, handlers added properly.

Is that like scriptmanager does its task async.. I mean may be sys object is not at all created and then it’s referring to sys via any AJAX control.

I missed out that I am using Telerik controls.

Pls Help!!

By: Mario Alvarez

Mario Alvarez — Wed, 01 Apr 2009 17:45:57 +0000

Hi. I was trying the solution that you post. But I still have the same error. One thing that I noticied was that in the JScript file (.js) the intellisense doesnt show the Sys Class. The Warning that I am reciving is:

“Error Updating JScript IntelliSense: (File Path).js: ’sys’ is not defined @ (Row, File)”

Any clue about this Error

Thanks for all

By: Mike Walters

Mike Walters — Mon, 16 Mar 2009 19:34:54 +0000

To all you people who are still having problems…. make sure your referenced .dll’s are all dated (created) after the AjaxControlToolkit.dll’s creation date

By: Dave Ward

Dave Ward — Wed, 11 Feb 2009 13:50:25 +0000

The first thing I’d check is that the ScriptResource.axd and WebResource.axd calls are still working properly when you move to 3.5.

By: Dave Ward

Dave Ward — Wed, 11 Feb 2009 13:46:26 +0000

Make sure any of your JavaScript code that references the PageRequestManager (like code that sets up BeginRequest and EndRequest handlers) isn’t executing until Application.Init.