Hello my friend, I think you should check out your version of this mod. It updated few months ago, the newest download link is: http://www.mediafire.com/file/xj2kz81kn7beiko/MQ9_PREDATOR_B_with_PILOT_STATION_2021.7z/file
Secondly, make sure your install position, install the mod in: Users/your name/ Save game/DCS/Mods/aircraft.
Hope it can help you. Have a nice day and enjoy your flight.