I'm a new member and own the yoko flight yoke by virtualfly. The sim recognizes it but I can't assign axis to it. All my other controls are assignable.
Strange, I have the Yoko, too, but axis assignment works just like for any other hardware. Try deleting axis assignments for elevator and aileron (select the axis and press del multiple times) until you have a blank entry, then select the axis again and move your yoke. Should work.