The type or namespace IHttpActionResult not found

Question

This is the first time I am creating a Web API application in ASP.NET MVC4. I opened a new Web API project and added a new controller named \'Product\'. The function given below

Answer 1

Using NuGet to install the Web API2 Core lib. dll. You may have to update Nuget before install ing Web API2 because some components in API2 not compatible with old Nuget package. I had done this way and problem was resolved.