Error AJAX after installing Cumulative Update on Sharepoint 2010

[Roberto]

Hello,
after installing the Hot Fix for Microsoft Knowledge Base article number(s) 2553048 for Sharepoint 2010 SP1 i receive this error on default page.

Webpage error details

Message: ASP.NET Ajax client-side framework failed to load.
Line: 196
Char: 34
Code: 0
URI: http://srv-sp2010:30000/Pagine/default.aspx

Message: 'Sys' is undefined
Line: 223
Char: 1
Code: 0
URI: http://srv-sp2010:30000/Pagine/default.aspx

Message: 'Sys' is undefined
Line: 1371
Char: 1
Code: 0
URI: http://srv-sp2010:30000/Pagine/default.aspx

Message: 'Type' is undefined
Line: 2
Char: 1
Code: 0
URI: http://srv-sp2010:30000/_layouts/sp.core.debug.js?rev=Qp5K7ycU%2FEY9IvE0KOi7zQ%3D%3D

Message: Object doesn't support this property or method
Line: 5
Char: 3
Code: 0
URI: http://srv-sp2010:30000/_layouts/cui.debug.js?rev=%2BhQl2NTQMTydPivdG%2Bq%2FdA%3D%3D

I use in my master page:
<telerik:RadScriptManager ID="ScriptManager"  runat="server" EnablePageMethods="false" EnablePartialRendering="true" EnableScriptGlobalization="true" EnableScriptLocalization="true"/>
 if i change with scriptmanager i don't have error.
<asp:ScriptManager ID="ScriptManager"  runat="server" EnablePageMethods="false" EnablePartialRendering="true" EnableScriptGlobalization="true" EnableScriptLocalization="true"/>

I use Telerik version 2010.1.309.35

Thanks.

[Marin]

Hi Roberto,

 You should check the permissions of the application to access the Telerik.Web.UI.WebResource.axd resource file. You can check the following help topic for more information on what modifications need to be done in the web.config file in order to avoid this error:
http://www.telerik.com/help/aspnet-ajax/introduction-troubleshooting.html

Greetings,
Marin
the Telerik team