If you are having a problem generating your book, the Versions page is the place to start.
Author > Books > (your book) > Preview or Publish > Manuscript Versions
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, you can email email@example.com and we'll help on a best-effort basis, during normal business hours. (We typically respond between 10 AM and 5 PM Pacific Time.)