In LV 2015, the AF was integrated into the project window, so you should be able to create both actors and messages by right clicking on items in the project. I haven't looked closely into this, but since you say you can't see it, I guess that means the MM was removed from the tools menu. The help for LV 2015 should probably have details on this.
Also, in general, the best place for AF questions is the AF group in the communities area.
___________________
Try to take over the world!
