RadScriptManager strange error : method get_EnableCdn ...

The error:

method get_EnableCdn in type system.web.ui.scriptmanager from assembly system.web.extensions, version=3.5.0.0, culture=neutral PublicKeyToken=31bf3856ad364e35' does not have an implementation.

The solution:

1. Delete this line from the pages you have it:


1 <%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>


2. Verify this section in your web config:

1 <runtime>
2 <assemblyBinding appliesTo="v2.0.50727" xmlns="urn:schemas-microsoft-com:asm.v1">
3 <dependentAssembly>
4 <assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35"/>
5 <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
6 </dependentAssembly>
7 <dependentAssembly>
8 <assemblyIdentity name="System.Web.Extensions.Design" publicKeyToken="31bf3856ad364e35"/>
9 <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
10 </dependentAssembly>
11 </assemblyBinding>
12 </runtime>


Very important: Make sure you use the: appiesTo in the following line:

1 <assemblyBinding appliesTo="v2.0.50727" xmlns="urn:schemas-microsoft-com:asm.v1">
2

3. If the error message remains or in the case you were not able to see your telerik controls in design mode (you have a very big an strange error instead of it), you could also try:
- Make sure you have Telerik.Web.UI.dll, Telerik.Web.Design.dll and Telerik.Web.UI.xml in your bin folder.

4. Verify that you have only one reference to System.Web.Extensions in your project (whether you have it in your bin folder or in your GAC)

More Info:

http://www.telerik.com/community/forums/aspnet-ajax/general-discussions/236690-error-rendering-control.aspx

http://forums.asp.net/p/1497738/3661536.aspx