Q:

ASP.NET Ajax client-side framework failed to load

I got this error: 

ASP.NET Ajax client-side framework failed to load

with the error:

'Sys' is undefined.

The error qppears in IE on the bottom (error message), and appears only when i'm running the site on server.  on my localhost everything works fine.
i moved for new server, and there i have the problem. in my previous server everything was fine. 
The problem comes from the SCRIPTMANAGER of the ajax.
what i can to do? somthing in the web.config, or should the host company need to install somthing?
ASP.NET 4, IIS 7.5
The ugly yellow triangle on the IE is not what is disturbing me.. the big problem is that the script manager with the update pannel - dont work !

A:

A quick solution is to update your web.config and add following section
<handlers>
    <remove name="WebServiceHandlerFactory-Integrated"/>
    <remove name="ScriptHandlerFactory"/>
    <remove name="ScriptHandlerFactoryAppServices"/>
    <remove name="ScriptResource"/>
    <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</handlers>

