I.e., as I understand it, maps are not generated through the NCF Excel file, right?
I haven't tried opening maps generated through a regular Excel file using the NCF. I tried generating maps using the NCF Excel file.

Added 1 minute ago
Could you please remind me where the link to the "correct version" of the clean core is located? It would be ideal if you could provide the link directly, as it's currently quite confusing and difficult to find.
The NCF thread only contains links to creature assemblies, and in several versions. What is the difference between "Buka" and the others, by the way?