P51D will Not complete installation after download

"supportdesk thetms.com" <[email protected]> Sun, 16 Dec 2018 17:18:01 -0600 (CST)
Newsgroups gmane.games.flightgear.general
Message-ID <1407002785.165950.1545002281816@webmail.networksolutionsemail.com>
Could not get the P51-D to install via Flightgear download screen.  Manually downloaded and installed.  It shows up on the INSTALLED screen when starting FlightGear but when trying to fly receive error message that plane in snot installed or needs update.
Tried to update via Flightgear update screen but continue to get extract/install error.

Help!
Ron