Several JS errors are trown when writing in re-focussed empty Editor in Chrome.

Video:  https://www.screencast.com/t/Wx6Ucs8m6S5w

First error's message:
RadEditor.js:10521 Uncaught TypeError: Cannot read property 'startContainer' of null


Steps to reproduce:
1. Open in Chrome: http://demos.telerik.com/aspnet-ajax/editor/examples/trackchanges/defaultcs.aspx
2. Switch to HTML mode and clear the whole content
3. Switch back to Design mode
4. Click any of the Bold/Italic/Underline commands
5. Click out of the Editor's element
6. Click back in the Editor's content area and start typing

Result: JS errors are thrown