Can you determine which page that fails when trying to create a preview PDF copy? This post in the link I posted about léonie may help:
inkeysNov 18, 2013 8:34 AM
Re: Issues with iPhoto files when trying to create a bookin response to léonie
Maybe I was a little harsh on iPhoto and ordering. Turns out I've fixed it via your suggestion; so thank very much!
Duped the project, then started a preview. Error happened immediately so deleted first image. Preview again and it progresses until page 16. Did the same and eventually previewed the whole book fine. Reinserted new pictures or resaved error photos; one final preview later and I'm uplaoding to order!
One thing I will note that didnt help. When it gets to say, Page 16 and there's an error, you need to count back 2 pages as it's not really Page 16 since the cover and inside flap are counted as Pages 1 and 2. Hope that helps somebody in the future.