When flying with B737 and using the FMC or ATC it is not possible to activate the ILS landing. The ILS works fine without using the FMC . When you press the APP (without the FMC programmed) in Autopilot the diamonds appear on the HSI for lateral navigation and glideslope which is great. However,when receiving instructions from ATC the ILS does not work when a flight plan in the FMC, everything else in the flight plan is fine. Is this a problem with X-Plane or am I doing something wrong?