Dividing eBook into two major parts not working

There’s a good chance I’m missing something in the manual, but I’ve tried several different ways to divide a long novel into two distinct parts, Book I and Book II. for the ePUB version. The result is a Table of Contents that’s inconsistent (Sometimes It shows Chapter # and chapter title, other times it adds the first line of the opening scene, which I don’t want) I Have yet to find a way to come up with a way of displaying the Book II title page, and the first chapter of Book II has disappeared, though it’s still there in Scrivener. Any ideas on how to make it work so the TOC and and all the chapters actually show up?!

Follow-up: With a bit of trial and error, I was able to convert the novel into a readable ePUB format. But when I ran it through IDPF’s validator, I received the following error message:

ePUB version 3.01/ Compiled in Scrivener
WARNING OPS/content.opf Line 5 Position 87, ’dc:identifier’ value ‘urn:uuid:ISBN 978-1-7333345-1-8’ is marked as a UUID, but is an invalid UUID.

Since this novel will be going through Ingram Spark, and they need it to be run through the validator process first, I assume I need to fix this, but I don’t know coding well enough to know what the the error messages means. Any iddeas on what I should do?

tom c.