(Please note, this does not affect Version 4+ of Prepar3D)
If you do not have nightlighting in FSX/P3Dv2/P3Dv3 it can be due to one of the following reasons:
1. Your simulator is not running as admin.
Try running your simulator as an administrator. This will allow all necessary DLLs to properly run and render the night textures.
2. Anti-Virus Conflict
Your Anti-Virus may be causing an issue as it may be blocking the DLL from running.
Try disabling your Anti-Virus when running the simulator. If the nightlighting appears, you may need to add an exclusion to your Anti-Virus tool.
The path for the exclusion: [Root Sim Folder]\SimObjects\Airplanes\TFDi_Design_717\Nightlighting
If it is still not appearing, you may need to reinstall the entire aircraft with your Anti-Virus disabled. To do this, follow these steps.
1. Open the addon manager and click the uninstall button.
(This will not affect your current install if you do not delete the items from your install folder.)
2. Click install after this is completed.
3. Run the simulator as an administrator with the anti-virus disabled.
4. Verify the simulator is properly displaying night textures in the cockpit.