IFilteringControl in Blend

[Sergey]

I have implemented: public partial class MyFilterControl : IFilteringControl {...}
VisualStudio 2010 Design surface has no problem rendering MyWindow with
<telerik:RadGridView>
    <telerik:RadGridView.Columns>
        <telerik:GridViewDataColumn ShowFieldFilters="True" >
            <telerik:GridViewDataColumn.FilteringControl>
                 <uc:MyFilterControl />
            </telerik:GridViewDataColumn.FilteringControl>
        </telerik:GridViewDataColumn>
    <\telerik:RadGridView.Columns>
</telerik:RadGridView>

Expression Blend 4 can't render the window and has an error:
The specified value cannot be assigned. The following type was expected: "IFilteringControl"

[Rossen Hristov]

Hi Sergey,

Can you please open a separate support ticket and attach the sample project that reproduces this error.

You should contact your license holder and ask him to add you as a licensed developer in order to be able to do this.

Thanks in advance. We are looking forward to hearing from you.

Best wishes,
Ross
the Telerik team