Microsoft.SharePoint.Taxonomy assembly issue in SharePoint 2010 custom code

If you create a project in Visual Studio 2010 Beta that implements custom code that uses the Microsoft.SharePoint.Taxonomy.dll assembly, when you try to compile the code, you'll get the following error message:

The primary reference "Microsoft.SharePoint.Taxonomy, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c, processorArchitecture=MSIL" could not be resolved because it has an indirect dependency on the framework assembly "System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v3.5".

As the error states, a wrong version of the System.Web.DataVisualization.dll assembly is being referenced. This is actually a design time issue that occurs in Visual Studio. Otherwise at run time .NET loads the correct version of the assembly. You'll run into the same problem if you use the Microsoft.Office.Server.Search.dll and Microsoft.SharePoint.Publishing.dll assemblies.

Microsoft has posted a simple solution for this problem. All you need to do is to add a reference to the System.Web.DataVisualization.dll assembly, which is located in the following folder:

C:\Program Files (x86)\Microsoft Chart Controls\Assemblies\System.Web.DataVisualization.dll.

Happy coding!