For G4:
Go to the "My Documents" folder and find a folder called "RealFlight G4".
Double click on that, then open the "Vehicles" folder. In there you will find a folder named "CustomModels" open it, Inside you will find the "Blade_400_3D_V2" folder open that. Now
download this zip file from here and extract the files to your desktop. Place the 2 files in the "Blade_400_3D_V2" folder and start up RealFlight, When
you load the Blade 400 3D V2 The error should be gone now.
For G5:
Go to the "My Documents" folder and find a folder called "RealFlight G5".
Double click on that, then open the "Vehicles" folder. In there you will find a folder named "CustomModels" open it, Inside you will find the "Blade_400_3D_V2" folder open that. Now
download this zip file from here and extract the files to your desktop. Place the 2 files in the "Blade_400_3D_V2" folder and start up RealFlight, When
you load the Blade 400 3D V2 The error should be gone now.
This same process also works under Vista, and Windows 7 as well.