I was working in a book in indesign. At the end of the book i had a long analytical index which i made using cross reference and anchor text. When i was at the middle of the work indesign crashed. I realized reading an old post referred to CS 4 CS 6 that you have to open all the book documents.
I write this so it maybe can help someone in the future and Adobe to fix this issue.
It seems crazy you have to open all of the book documents. I have over 160 Indesign documents to make up an 800+ book. I can't even open all of the documents in order to generate an index. I'm guessing I'll have to combine documents where practical to be able to generate the index.