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'Sys' is undefined. and 'Type' is undefined. Javascript error messages with ASP.NET AjaxControlToolkit

Hello all,

I sometimes suffer from the 'Sys' is undefined error messages while developing or working on ASP.NET web sites which ASP.NET AJAX is enabled.

Recently, in an ASP.NET web site application which uses the AjaxControlToolkit I again get the above 'Sys' is undefined and 'Type' is undefined javascript runtime error messages.

After I have reconfigured and edited the web.config file httpHandlers section, I was able to correct and solve the problem.

<httpHandlers> section is under the <system.web> web.config configuration section.

Below is the <httpHandlers> section I'm using without any runtime errors.


<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
<add path="Reserved.ReportViewerWebControl.axd" verb="*" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" validate="false"/>

Published Thursday, January 03, 2008 11:22 AM
Filed Under: , ,



Eralper's Blog on Software Development said:

Hello all,

Recently, I had created an .aspx page and added the ASP.NET Ajax Tab control from the Ajax...
June 9, 2008 7:38 AM

saikumarp said:


I am really thankful to you for making my day. Problem for "Sys Undefined" is solved by placing the tags in <HTTPHANDLERS>.

Thanks for your post.

-- Sai
September 25, 2008 11:23 AM

Bluto said:

Thanks a lot! That took care of two problems for me.
November 9, 2010 11:17 AM

eralper said:

I'm happy to see that my experience with this problem could help you! Thanks for your feedback :)
December 16, 2010 12:24 AM
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