RoutePrefix Not Found in WebApi 2,2

Question

I have build a Web API 2.2 project using Visual Studio 2015 Community Edition. Attribute RoutePrefix is not found. After searching the internet, I found PM Console Command : Update-Package Microsoft.AspNet.WebApi.Core -reinstall. It solved the problem but as soon as I right click on the Solution and Click Rebuild Solution. Attribute RoutePrefix again starts giving error of not found. Can anybody tell me what is wrong with Visual Studio.

Answer 1

Add a RoutePrefix attribute to the controller. This attribute defines the initial URI segments for all methods on the controller.

[RoutePrefix("api/Employee")]
public class EmployeeController : ApiController
{
    // ...
}