Hi islandavid
I'm not with Laminar Research, just a fellow simmer in the UK, but I would suggest the following simple steps:-
1. Delete any folders/files associated with the RealSimGear GNS530, which is probably a plugin.
2. Run the X-Plane 11 Installer app, as this will determine which of your folders/files are missing or corrupt and download those only to be installed on your PC.
3. Run X-Plane 11 again to make sure all is OK and if not, attach your X-Plane 11 Log.txt file and X-Plane Installer Log file to this post for review.
Regards and please advise outcome?