"Ghost" file reference survives *deleting* and re-creating a project!

I’ve been trying to refactor a project created from a marketplace project, and basically every time either the editor fails to rename everything correctly, or corrupt the assets, or, as of today, downright crashes. Anyway, in my previous attempt, I had created a directory called “CoreAssets”.

Now, I’ve deleted that (corrupt) attempt, and recreated the project (yet again) from my vault. And when I open that project for the first time, there are 3 yellow warnings in the log, saying the editor cannot find files from “CoreAssets”!

How can the editor try to load files that were defined and used only from a deleted projects?!?