Two 100+ page large square books have arrived almost completely blank.
The only thing I can think of is that I may have cancelled the upload process on both before then resending and leaving to complete. Left the upload processes to complete and returned an hour later - no error message. Quick check at Blurb and seemed OK.
Have had about 20 photo books successfully printed using the book module before. Never had any issues.
Once sent to Blurb, the preview UX is tiny.
Please get some kind of checksum operation to confirm books have been successfully uploaded.