Invalid book-scope Value
project
A
book-scope value was not book or chapter.
Q-5-43 — Invalid book-scope Value
A
book-scopevalue was notbookorchapter.
What this means
A book-scope value was ignored because it is not book or chapter.
none is not accepted as input: it is what a render reports when no book mode applies (the project is not a book, or the file is not in the chapter list). A value that is not a string is invalid too. The next layer down (runtime, document, _metadata.yml, project) applies instead.
How to fix
Use book or chapter, or remove the key.