Instructions:
In IE11 when we select an image and change from Design to HTML mode or try to apply any paragraph style to it, the browser gets unresponsive. 

To get a better understanding, please refer to the following videos:
http://screencast.com/t/xufHlK0bew
http://screencast.com/t/YcVcqygVY7GE

Demo page: http://demos.telerik.com/aspnet-ajax/editor/examples/overview/defaultcs.aspx?skin=Default