I'm trying to upload my book to Blurb from lightroom 5.6 but i found an error during font conversion (OS X 10.9.5), also using different font types.
If i select the the book conversion to pdf format or jpeg everything is completed without errors (most of images are in raw format).
I am sorry to read about the upload trouble. This sounds like a font issue. Have you tied a different font to see if the file will then upload? If you have, and continue to have trouble, please contact our customer support team here:
We'd be happy to troubleshoot the problem with you.
Blurb Customer Support