[Solved] VS2008RTM: Cannot add Telerik.Web.UI.dll to Toolbox

[Melvin Lee]

Hi,
I have a fresh installed machine (Windows 2003 R2 SP2) with Visual Studio 2008 RTM installed and also installed Prometheus (2007 2 1107) trial and hotfix.
When I try to add the Telerik controls to my toolbox, I get the following error

There was an error loading types from assembly 'C:\Program Files\Telerik\RadControls 'Prometheus' for ASPNET Q2 2007\Bin\Telerik.Web.UI.dll' 'Could not load file or assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.'

Any idea what I have to do to make it work?

[Ubong]

Hello Marvin ,

This is a known problem which arises due to the fact that RadControls Prometheus are built for System.Web.Extensions 1.0 and if you do not have System.Web.Extensions 1.0 installed on you machine, you will receive this error.
So if you do not have the System.Web.Extensions 1.0 dll in your GAC, you get the error and you cannot add the controls to the toolbox.
You can solve this using one of these two approaches:

1. install ASP.Net Ajax Extensions 1.0 (System.Web.Extensions 1.0) only in order to be able to add the controls into the Toolbox
   
2. Manually add the Telerik.Web.UI.dll in your bin folder and register the tag in your page header :
   
   <%@ Register TagPrefix="telerik" Namespace="Telerik.Web.UI" Assembly="Telerik.Web.UI" %>

Kind regards,
Ubong
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Brad]

Will the Q3 2007 version of Prometheus be built with the 3.5.0.0 version of System.Web.Extensions?

[Ivo]

Hi Brad,

Yes, we will have an ASP.NET 3.5-specific version of the Telerik.Web.UI.dll with our Q3 release.

Regards,
Ivo
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center