I have tried deleting the aircraftDB.pye file and running the Live Updater, but the file it re-creates was modified on 17th Feb 2017 and GSX still requires the parking brakes to be set to start services.
The previous user confirmed that doing this will result in getting the correct updated file.
Should I try a complete re-install of GSX?
Won't make any difference. The only file involved is the aircraftDB.pye and, the only sure way to get the current version is to remove it manually. Well, of course, it's not necessary, because the updater will surely update it but, if it doesn't work, removing will surely get the latest version.
If it doesn't on your system, maybe some kind of external product (antivirus ?) is preventing the updater to work properly. Try to remove this folder too:
%APPDATA%\Virtuali\UpdateCache
And see if it finally download the correct file.