Hi Declan ,
Thank you for writing and for your feedback.
This is not desired behavior but I am afraid that I could not reproduce the issue you described during design-time. I tried loading MainPage.xaml that is part of the Examples project and the What's New control that is part of the QSF project. It is probably fixed in the latest build. Please indicate which other pages cause the designer to fail to load so that I can inspect them and make sure that everything works.
I am looking forward to your reply.
the Telerik team
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