My book is stuck on "Generating outline…" at 0 chapters, even after restarting BookyAI. How do I fix it?

Update to BookyAI 1.9.14 or later and open the book. In earlier versions that line was shown whenever a book had no chapters, even when the outline request had failed (for example because the API key was rejected) and nothing was running. Since 1.9.14 the page says "The outline was not generated", shows the reason, and has a "Generate the outline" button that starts the same book again. Your Codex, author notes and series are untouched. First make sure your AI engine works: in Settings, save the key and click Test. You do not need to rename or delete any file in the book's folder.