It's because the apron light models are the same for RDP-LIRN and RDP-EHRD but LIRN doesn't have the textures in it's folder.
MSFS loads LIRN over EHRD because of it's load priority and therefor loads the LIRN assets without a texture and doesn't load the ones for EHRD.
If you copy these textures/files;
LIGHTV1_BASE_COLOR.PNG.DDS
LIGHTV1_BASE_COLOR.PNG.DDS.json
LIGHTV1_BASE_COLOR_EMIS_PNG.PNG.DDS
LIGHTV1_BASE_COLOR_EMIS_PNG.PNG.DDS.json
LIGHTV2_BASE_COLOR.PNG.DDS
LIGHTV2_BASE_COLOR.PNG.DDS.json
LIGHTV2_BASE_COLOR_EMIS_PNG.PNG.DDS
LIGHTV2_BASE_COLOR_EMIS_PNG.PNG.DDS.json
from
Community\rdpresets-ehrd-rotterdam\scenery\rdp\texture
to
Community\rdpresets-lirn-naples\scenery\global\scenery\RDP_LIRN\texture
And add them to the LIRN layout.json it fixes the problem.
I've also attached the working layout.json with the textures added, you only have to copy those textures to the right folder.
layout.json
