Aw, Understood.
Shortly after my first reply, I completely deleted and reinstalled my GTN750 and it works fine. Apparently after the last X-Plane 11.50b9 update, that install corrupted my Reality XP license code, thus causing the error Msg. With the reinstall, the problem appears to have been repaired.
I must say, I deeply appreciate your quick responses and willingness to help with the issue. Another reason I am so pleased to have purchased this wonderful product. Thank you again.