Seems that the default GWB Ceiling is not allowing lights to be copied or arrayed (unless you use the Radial Array). It gives the old 'Can't place inserts outside of hosts. These elements won't be copied.' message. It's weird because when you turn the ceiling into an ACT type, the lights can be copied and arrayed fine. After this you can turn the ceiling back into a GWB and there is no error message.