This is from Omzy's field pack lighting effects. If you choose "remove glitched lighting" from bootleg you'll get rid of all these, I think; but you'll lose all the hi-res lighting completely. Kinda funny that no one has ever gone through the game and only removed the ones that need adjustment, but we want Omzy to fix them.
If I ever get around to actually doing a full playthrough again (life and my obsession with mods themselves have prevented this for quite some time) I would like to make a list of the scenes that actually need to have their hi-res lighting removed, for a future batch file-removal process. If someone could do that that would be great. Who knows, that might even be helpful to Omzy.
It's the best way to play anyway, without removing the glitched lighting. When you run into a scene that has a bad glitch that is somehow really ugly or game breaking, you can see which scene it is with aali's popup feature (shows the name of the file that is glitching onscreen during play). I think it shows this same message in the APP.log, as well. Then all you have to do to fix it is remove... erm... remove the file in that folder (ex. .\mods\*.*\field\woa1\woa_1_16_00.png) with the 15 on it or the 16... I'm a little "iffy" on that part. I'm not sure if it's always the same one, both the 15 and the 16, or what. You would need to do a little trial and error. Sounds like a fun project for a new member to make a big contribution to the rest of the community, if you could post a full list of all the scenes that needed to have files removed.