In one room I used region lighting levels for quite some time, but somehow it doesn't work anymore. I'm not sure but I think I turned it off some day because I tested several backgrounds in the same room. The point is I don't know how to turn it on again or why it doesn't work anymore. The lighting setting of the characters in that room are all set to true and there doesn't seem to be anything region/lighting related in the room's script. The regions in the room still have their lighting levels set..
So my question is: What could be a possible cause or is there any way I could have turned off the lighting aside from the characters setting?
Did you import a 256 color background or change the character sprites to 256 color ones?
No, all the sprites and characters are 32-bit. And while it could be the case that I imported wrong colored images, I'm still using the old background and mainly old sprites who were affected by region lighting some time ago.
Okay, it's solved.
I was constantly tinting the characters in the rep-ex which of course counteracted the area lighting.