providing that error message wouldve been a massive help :D

you must have done some changes in your quake/id1/gfx directory that got rid of the palette. 

I'm making my first map in Trenchbroom. I set a light key in worldspawn just so I could see perfectly while testing some stuff. However, I now can't figure out how to return to default blackness. I tried both removing the light key from worldspawn and setting it to 0 but either way the world is still bright despite there being zero lights. Can I have some help with this? 

Are you running light.exe on your bsp? If not it will always be fullbright. 

Yep, I'm using light.exe. And have tried a few different exe's but nothing is changing. 

If your map has no light entities in it, the map will be fullbright. As soon as you add even one light entity, all the non-illuminated areas will become dark. 

Thanks! I had a feeling it would be something stupidly simple / obvious... 

Is there a way to make one specific room in a map look fullbright other than stuffing it with maxed out lights? I had this idea of making a funny "noob mapper" secret with blocky offgrid architecture and texture misalignments aplenty... 

Is your friend.

Check out my SM185 entry for a good use case. 

 

Make sure you use the exit texture on a wall. The entire wall. And columns that have gaps under them not touching the floor. And a door that flickers through a wall when it's open. 

Thanks for the ideas, Qmaster! 

If you want more inspiration, play SM49. The theme was "crappy
Maps"

https://www.quaddicted.com/reviews/sm49_pack.html