I just upgraded from 2014 Q2 to 2014 Q3 for WPF and I am running into an issue that looks to be specific to the Windows 8 Touch theme on the TabControl.  I set the application wide theme using the following in my first window that loads:

Telerik.Windows.Controls.StyleManager.ApplicationTheme = new Telerik.Windows.Controls.Windows8TouchTheme();

On a subsequent window that loads that contains a RadTabControl, the application will throw an exception:
System.Windows.Markup.XamlParseException : Provide value on 'System.Windows.Baml2006.TypeConverterMarkupExtension' threw an exception.
The inner exception is:
System.Xaml.XamlParseException : Prefix 'telerik1' does not map to a namespace.

The exception is throw from the ShowDialog() method being called on that window.  The kicker is that if I comment out my application-wide theme or switch it to the standard Windows 8 theme, the issue goes away, but obviously I am not using the theme I would like to.

Anybody run into this before or have any suggested workarounds to it?

Okay, I figured out a way to fix this, at least for my situation.  I switched away from setting the theme application-wide using the ThemeManager and setting it using implicit styles in the App.xaml.  The documentation that I used is at http://www.telerik.com/help/wpf/styling-apperance-implicit-styles-overview.html.

Hello Bob,

Sorry for the inconvenience caused.

We are aware of this issue and it is already logged in our Feedback portal, where you can track its progress and vote for its fix. 

I am glad you managed to handle this behavior on your own. Please note that we strongly suggest to use our Implicit Styles in combination with our NoXaml binaries. You can find more information on that matter in our blog post “XAML Theming – Implicit Styles versus StyleManager”.
Regards,
Milena
Telerik