Nikon D5500 Reference Manual page 54

A
Lenses with Retractable Lens Barrel Buttons
Before using the camera, unlock and extend the lens. Keeping the
retractable lens barrel button pressed (q), rotate the zoom ring as
shown (w).
Retractable lens barrel button
Pictures can not be taken when the lens is
retracted; if an error message is displayed
as a result of the camera having been
turned on with the lens retracted, rotate
the zoom ring until the message is no
longer displayed.
30 Introduction