That looks like a corruption in the VSExtensions. I recommend uninstalling and reinstalling it, then try again. Additionally, there was an update today, please try again with the new version (2017.2.522.10).
Make sure you have all Visual Studio installations closed before performing the install.
Lance | Tech Support Engineer, Sr.
Telerik by Progress
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items