The current type is an interface and cannot be constructed. Are you missing a type mapping?

I have a controller class that takes care for the double click command and in turn calls a method that popups a window to the user. Something like :

var popup = container.GetService<PopupCommand>();

In the above line it throws an error saying : The current type, PopupCommand.IPopupDataHandler, is an interface and cannot be constructed. Are you missing a type mapping?

I updated the DLL that contained a method for container.GetService(), before that it used to work fine.

I tried searching in google, but the issues similar are more related to Unity, and i doubt whether my issue is anywhere related to Unity.