If you are having a problem generating your book, the Versions page is the place to start. You can find this page by going here:
...making sure to replace YOUR_BOOK with your book's unique web address.
From there, you can see which book generation attempts succeeded or failed.
Every time you try to preview or publish, we store a version of your manuscript.
(For the programmers: this is a Git repository, and we don't provide direct access to it for authors, so that there are no merge conflicts.)
If you click "create archive", we will create a zip file of that version of your manuscript that you can download.
So, if something has gotten broken, the best thing to do is to click "create archive" on the most recent version that worked, and the first version that broke, and compare them to see if the problem appears.
(Again, if you're a programmer,
diff is your friend here.)
Finally, if you can't figure it out this way, please check out Author Support Guidelines to hopefully find the quickest path to a solution. We've worked with thousands of authors over the years and these guidelines can save you tons of time as you work on your books and courses.