error loading gps engine, the flight plan will not be used

Hello,

I am using FSX - Steam Edition with the following addons:

FSUIPC (paid version)

GSX

Ultimate traffic Live

Active Sky 2016 for FSX

PF3

Carenado addon aircraft Premier 1A

Windows 10

I create flight plans from simbrief, download them, place them in my documents Flight Simulator X folder, start FSX, go to free flight, "flight Planner" click "load" and load the flight plan that I just downloaded from simbrief.  I have FSX transport my aircraft to the airport, plug in all of the waypoints and altitude into the FMC (Proline 21) and start the flight.  I then often will save midflight and exit FSX.  Upon loading my saved flight from FSX, I get the error message "error loading gps engine, the flight plan will not be used."  I then load the saved flight and all of my data in the FMC is gone.  Does anyone know how to fix this so that I may save a flight, come back to it and have all of my waypoints, SID/STAR data and altitudes, etc., saved so I can continue my flight.  I appreciate any help with this topic.  I have googled it and searched but have not found a solution.

Thanks,