I'm facing the problem with menu "Selected" Meny options e.g. "Set material to faces" or "Double sided faces" are not active. My version is 4.8.1a but problem was present also in previous versions. Any ugestion what is the reason and how I can fix that?
Did you confirm which elements you can select?
These menus are enabled only when you select at least one face. And, you cannot select any face when the [Fc] button in the [Edit option] is off.