Before compilng/building the project, you will need to re-export the models using the Flight sim 2024 material (for the emissive texture to function) and also re-apply spot lights using the new 2024 SDK lights in MAX/Blender.
Spots lights that are coming from the MSFS2020 blender exported will not work when creating (upgrading) your current projet into MSFS2024.
As @emilios said juste above, you will need first to convert your MSFS2020 blender/max project to MSFS2024 using the integrated feature and then export and finally build your project.
You can fin the related documentation here for 3DS Max, or in C:\MSFS 2024 SDK\Tools\Blender\addons\io_scene_gltf2_msfs_2024\documentation for the blender export