I checked again and might be this error is raised due to I moved the Rocket Pocket folder from Xplane/Aircraft/X-Aviation to Xplane/Aircraft/Extra Aircraft, becuase all other aircrafts are stored there. Strange but after I re-installed everything and keep the folder as default this error didnt occur anymore.
Outstanding plane...a lot of fun to fly.....but, the AviTab tablet does not light up? Do I need the external plugin (which I have) or not? Sorry for the confusion.