Hello Denis,
You'll need to remove the references to "Telerik.Web.UI" in the web.config file as they are outdated and cause errors. Also if you find reference to "Telerik.Charting" in some of the example's web.config files - please remove them too:
This will be fixed in the next courseware.
Please accept my apologies for the caused inconvenience.
Best wishes,
Veronica Milcheva
the Telerik team