Razor Views: Intellisense not working with C # 3 for class libraries

I use class libraries in my ASP.NET MVC3 project.

To get the job done, I did the following:

• Using areas
• Using custom VirtualPathProvider
• Usage BuildManager.AddReferencedAssemblyfor each assembly
• Csproj files changed to add support for Razor / wizards ( <ProjectTypeGuids>{E53F8FEA-EAE0-44A6-8774-FFD645390401};{fae04ec0-301f-11d3-bf4b-00c04f79efbc}</ProjectTypeGuids>)
• Copied web.configfrom a web project to each class library project

Everything works, except for intellisense in razor looks. I get warnings like this:

The lambda expression function cannot be used because it is not part of the ISO-2 C # language specification

Class libraries are configured to use .NET 4.

There are several other questions regarding the same problem.

• Razor intellisense: , ISO-2 #
• MVC 2 VS 2010 View Building Error: " " , ISO-2 #

, 2.0 ( ?)