RadWindow as a UserControl HRESULT E_FAIL in Blend 4

[dwhite]

I created a "UserControl" that acts like a RadWindow.  The steps are outlined in this HowTo. 

This is a plain control, nothing additional in the code-behind (like service calls or anything, just a call to InitializeComponents() like in the example).

This is Silverlight 4, and opening the "window" within Blend 4, I can't get design-time support.  The error is:

"Exception: Error HRESULT E_FAIL has been returned from a call to a COM component."

The source code is just:

<telerik:RadWindow
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:telerik="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.Navigation"
    mc:Ignorable="d"
    x:Class="Sample.UserControl1"
    d:DesignWidth="640" d:DesignHeight="480">

    <Grid x:Name="LayoutRoot"/>
</telerik:RadWindow>

I've worked around it by putting all my content into yet another UserControl, but this isn't the best solution.  With my current approach, I have a lot of pass-through methods and bindings going on.  Note that Blend 4 fully supports a ChildWindow.  Also the designer in Visual Studio 2010 renders it perfectly, but I prefer to do my designing in Blend.

The file version of my Telerik.Windows.Controls.Navigation is 2010.2.812.1040

Thanks in advance for your help.
-Damien

[George]

Hi Damien,

I tried to reproduce the problem with RadWindow in Blend 4, but to no avail. Could you please specify on what OS you are running Blend 4.

I will be glad to assist you further.
 

Best wishes,
George
the Telerik team

[dwhite]

I'm running Windows 7 x64 with Blend Version 4.0.20525.0.

-Damien

[George]

Hi,

Could you check if your project has references to Telerik.Windows.Controls.Navigation and Telerik.Windows.Controls? Also, if you send a running sample that reproduces the problem it would be of great help.

I will be glad to assist you further.

All the best,
George
the Telerik team

[dwhite]

I ended up solving the issue.  In the project I was referencing the two assemblies from outside of the GAC.  Once I changed the references to the GAC, Blend started working...

-Damien