Strange behaviour of a UserControls with custom Template in VS designer
<p>I'm using a MS WPF Ribbon library in my project. The behaviour of the RibbonToggleButton does not match to my requirements. So, i've copied ControlTemplate of the RibbonToggleButton and added it's modified copy into my XAML. </p>

<p>When i reassign template to my modified one, the control could not be selected from VS designer and it does not show image. And when i'm selecting a node in XAML, designer marks the place, where should be the control, with a border (just like the control is selected).  When i use default template - everything is OK.</p>

<p>The control with the modified template works in the compiled application as expected. But maybe there is some side effects, that could affect application? What is the reason for such strange behaviour in the designer?</p>