Cannot create Controller with actions using Entity Framework

I've created a Model using Model first and Entity Data Model of Entity Framework. Well, when I want to create the controller (right click on controllers folder Add->controller->WebApi 2 Controller with actions using EF) then I become after defining the inputfields an error message: there was an error getting the type "WebApi.Models.QR_Name". Try rebuilding the project. The same error getting by the other Model class. How can I solve this??