[This article was last updated on March 19, 2020. If you think this article needs improvement or updating, please contact us by clicking the little icon at the bottom right of your browser!]
Step 15 book generation errors occur when the PDF version of the book fails to generate.
If this is the first time you're encountering this error, its cause may be due to a change you have made recently. Undoing your recent changes and then trying again to see if you can narrow down the issue is a good next step.
Here's an article we've prepared that should guide you to the more detailed resources you may need for resolving this issue:
If none of those resources helps, please read our Leanpub Author Support Guidelines, for some information about what to do next: