I am experiencing the same issue described above. I have the database downloaded to my e:/ drive, but the GTN trainer and the GTN in X-plane say the "Database Not Found", and shows a blank black background when I turn it on.
I have found the applicable lines in Regedit, but I don't know how to make it right.
BinPath C:\Program Files (x86)\Garmin\Trainers\
DataPath C:\ProgramData\Garmin\Trainers\
DBDataPath does not exeist.
GtiExePath E:\Garmin\Launcher\GTI\GTI.exe
LauncherExePath E:\Garmin\Launcher\Aviation_Trainer_Launcher.exe
The below referenced files are on my E: drive.
There is also the 1GB terrain.tdb file in the same folder.
I have read the entire RealityXP manual several times, and re-read page 21 several times more. I don't know what I am supposed to do with that information.
Thanks for your help!