Microsoft JScript runtime error: 'Sys' is undefined

Question

Hi,

I am having problems with an intermitent error in an ASP.Net Ajax enabled website. The error I am receiving is the old faithful "Microsoft JScript runtime error: 'Sys' is undefined" error. Googling this error usually turns up the suggestion to add the correct "httpHandlers" and "httpModules" into the "web.Config" file. The web.config file for this project already has the following lines for those two sections. See below:

<system.web>
    <httpHandlers>
        <remove path="*.asmx" verb="*"/>
        <add path="*.asmx" verb="*" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
        <add path="*_AppService.axd" verb="*" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
        <add path="ScriptResource.axd" verb="GET,HEAD" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
        <add path="Telerik.Web.UI.WebResource.axd" verb="*" type="Telerik.Web.UI.WebResource" validate="false"/>
        <add path="Telerik.ReportViewer.axd" verb="*" type="Telerik.ReportViewer.WebForms.HttpHandler, Telerik.ReportViewer.WebForms, Version=3.0.9.430, Culture=neutral, PublicKeyToken=a9d7983dfcc261be" validate="true"/>
        <add type="Telerik.ReportViewer.WebForms.HttpHandler, Telerik.ReportViewer.WebForms, Version=3.0.9.430, Culture=neutral, PublicKeyToken=a9d7983dfcc261be" path="Telerik.ReportViewer.axd" verb="*" validate="true"/>
    </httpHandlers>
    <httpModules>
        <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </httpModules>
</system.web>

The error is intemittent, it sometimes does not present at all when debugging a page, and other times it will present constitently for anything up to a day or so? Please can anyone else suggest another area which may require attention.

BTW, we are using Telerik ajax controls on the page. One of our custom JavaScripts does render before the scriptmanager. ahve tried using both "RadScriptManager1.RegisterClientScriptBlock(...)" and "ClientScript.RegisterClientScriptBlock(...)" but both seem to render the script block above the "Sys.WebForms.PageRequestManager._initialize(...)" line.

Any help apprecuiated. Thanks in advance, Best regards, Duane.

Answer 1

instead of

Sys.WebForms.PageRequestManager._initialize(...)

do

$(document).ready(function(){
    Sys.WebForms.PageRequestManager._initialize(...)
});

(yes, jquery)