lights are affected, too.
first Pic : heli-hangar in UFORadiant, showing the lights.
Second picture : the night version of the map. Not so good.
After this I replaced all origin textures. No effect.
Next I removed the func_door in level 3. No effect.
I put the door in level 3 back and removed the func_door in level 2. This looks as it should now, I think.
I put the door in level 2 back and remove the func_doors in level 1. Again lighting seems ok, as in the third pic.
Putting doors on level 1 back for cross-checking again shows the problem I started with.