When a Kendo UI RadioButton is bound to a null or undefined value, an uncaught TypeError exception fires.
Please take a look at the following Progress Kendo UI Dojo which demonstrates the error firing.
When a null or undefined value is set, the RadioButton should be set to false.
The commonly understood semantics for radio buttons is that the selected radio button is filled on the inside (e.g. with a foreground color). The new styling does not fill the inside, and as such is a bit more confusing. I had to do a double-take at first, even though I had developed the screen I was looking at. It's important for a design to use standard and shared understandings that immediately communicate with the user.
Change the style back to a filled in circle, and for the Bootstrap 3 theme in particular please change it back to match Bootstrap 3.