Use the new implict mechanism. Attach the Windows8 _Wpf project instead of Windows8 dll. Xaml parse exception occurs runtime - "Cannot set unknown member 'Telerik.Windows.Controls.MaskedInput.PreviewInputTextBox.IsReadOnly'." Note: you can try the workaround added here: http://stackoverflow.com/questions/6850713/weird-xaml-parsing-error-when-trying-to-set-textbox-isreadonly
If you don't use Windows8 theme as a project, but you use it as a Styles in Telerik.Windows.Controls.xaml and Telerik.Windows.Controls.Input.xaml you can try setting these resource files BUILD Action to PAGE, not Resource.
I'm struggling with this error, do you have a workaround? Ive tried with the project and dll reference no luck. Thanks