If for some reason Naked light couldn’t find an image to show for an item in your library (typically due to another bug or you deleting stuff willy-nilly in the library folder in the Finder), Naked light would just keep trying to find it. And trying. And trying.

And taking up about 100% of one of your CPUs even when idling.

A one line fix. The library has two code paths: preview versus high quality. With no image, it would continuously render previews because it never get the OK to switch to a high quality rendering. Now, if it can’t find an image, it doesn’t even bother drawing that nothing again in high quality.