If time is set to night hours, environmental lighting (IE Lightposts) will occasionally not initialize. Seems like this occurs most often on the first time loading into the game.
- Legacy ID
Seems fairly random.
I get this problem too...
I have to load the mission twice otherwise the lighthouse to the south doesn't work. It's just sat in darkness.
There was another separate issue raised about this (which I commented on) but it seems to have disappeared.