Why is it asking me to save my documents for a new book?

I have 5 versions of the same book, but the last version was accidentally saved inside the 4th version.

I figured I could just move it to the same level as the fourth version and update links. After a couple of hours of total choas and not getting links to update, I decided no problem I'll make a new book.

I had all of the chapters of the book and the frontmatter and backmatter saved in one folder. All of the artwork was in a folder inside the parent like this:

==================================

Version 1

---->00 frontmatter.indb

---->01 ch1-name.indb

---->02 ch2-name.indb

---->03 backmatter.indb

---->Bookname, ed1.indb

Version 2

---->00 frontmatter.indb

---->01 ch1-name.indb

---->02 ch2-name.indb

---->03 backmatter.indb

---->Bookname, ed2.indb

Version 3

---->00 frontmatter.indb

---->01 ch1-name.indb

---->02 ch2-name.indb

---->03 backmatter.indb

---->Bookname, ed3.indb

Version 4

---->00 frontmatter.indb

---->01 ch1-name.indb

---->02 ch2-name.indb

---->03 backmatter.indb

---->Bookname, ed4.indb

Version 5

---->00 frontmatter.indb

---->01 ch1-name.indb

---->02 ch2-name.indb

---->03 backmatter.indb

---->Bookname, ed5.indb

Artwork

===================================

This allowed me to centralize my artwork and just keep addition editions as necessary.

But when I go into the folder for Version 5 and try to create a new book, Bookname, ed.5.1.indb

and then add the chapters in the Book Panel, it asks me to save each chapter. I don't want to resave each chapter, I just want to use the existing documents. Why is it asking me to save? The document is right there.