I was trying to compile an inherited VB .Net code that uses .Net 3.5 framework. When I compiled, it gave the following error
The type or namespace name 'DataVisualization' does not exist in the namespace 'System.Web.UI' (are you missing an assembly reference?)
Whatever answers I tried to find online could not give me details for .Net 3.5. I would get answers for .Net 4.0 and above but not for .Net 3.5. Microsoft documentation did not provide any hint. Finally I found out that there a Microsoft Chart Control for .Net Framework 3.5 that I need to install. Once I installed that program, solution compiled without any issue.