I have been living my life writing web apps with MVC5 until I ran into this weird problem. It happened because I put a generic method in my controller (I had a base controller, but that's by the way). I implemented some functionalities using Command Pattern and thought I could retrieve my command handler within a controller using the simple call:
var handler = CommandHandler<TCommand>(); handler.Handle(command); Well, I got the error: Cannot call action method on controller because the action method is a generic method.