MVC - Fix Error - The type or namespace name 'DataVisualization' does not exist in the namespace 'System.Web.UI'

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Error    CS0234    The type or namespace name 'DataVisualization' does not exist in the namespace 'System.Web.UI' (are you missing an assembly reference?)    

 

Error when using

using System.Web.UI.DataVisualization.Charting;

 

to fix it add reference to 

System.Web.DataVisualization