Hi Jake, Morgan,
Telerik UI for Windows Phone 8 targets only Windows Phone 8 and Windows Phone Silverlight 8.1. It is not supported on Windows Phone 8.1 as this is an entirely different XAML stack.
We're currently working on building a Windows Phone 8.1/Windows 8.1 (universal) suite that will enable you to write apps for Windows Universal and continue using the features of Telerik UI for Windows Phone.
Can you please try changing the locale on your phone to see if a crash will occur because of missing resources?
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