Element 'NChartControl' is not a known element.
This can occur if there is a compilation error in the Web site, or the web.config file is missing.

And i cannot paste module chart or dragdrop it on aspx page or ascx because i use this version "dotnetvision2010Vol1VS2010.zip"
i try to install new version "dotnetvision2011Vol1VS2010.zip" it not work
and i come back to "dotnetvision2010Vol1VS2010.zip" it still not work