Why can't I reference System.Web.Extensions in a Console application?

Question

The assembly is not in the list in the Add Reference... dialog. When I find it manually and add it, it has a small exclamation point over it and I can't seem to refer to it in code.

I tried it on 2 different copies of VS2010 with same results.

Answer 1

Change Target Framework from Client profile to the full framework and you will be able to add it.

Answer 2

Console applications, by default, target the ".NET Framework xx Client Profile" that doesn't include the web assemblies. Change the target framework to ".NET Framework xx" in Project -> Properties -> Application.

Answer 3

It is most likely because of the framework version that your project is targeting.

If you are targeting .NET 4.0 Client Profile, web assemblies are not included. Change the project to target 4.0 and you should be good.