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

I had a similar problem when I checked out a project from my source control.

I had the reference to Microsoft ASP.NET Web API 2 in the project but i still couldn't compile the project.

The solution was to re install the package using the Package Manager Console:

PM> update-Package Microsoft.AspNet.WebApi –reinstall