There is no way to fix it.
The warning only appears depending on which light option you have selected. The warning is the game saying "OMG I need to project a light here but that light doesn't exist" because the game doesn't recognize the difference between a light that SHOULD and SHOULDN'T be there.
That's why with any base game vehicle with a ton of lights, the lights aren't removable because it throws this small house keeping error. I promise this has zero effect on the performance of the mod or your game.