Book Module: "An error occurred adding text and fonts to the book"

I have this problem. For me it has occured AFTER I have already sent the book to Blurb and received the printed copy. Even without making any changes to the book, it now comes up with this error. (I did not save the pdf when I first sent it to Blurb and now want to send a pdf to a friend). 

I have tried every published method I can find and have never been able to print the pdf again. I have printed around twenty books created in Lightroom and this error now affects five of them. It seems to be totally random and has existed for at least seven years that I can tell by reading various forums and Gogle searches. I have never seen any acknowledgement (or solution) direct from Adobe. Very annoying!

Some notes I have accumulated from other forum threads in the past that might be helpful- Read in the notes about 'Finding' book errors.

Experiment with a COPY of your book and work your way through them and  until you find the problem. Good luck.

First- Duplicate the Saved Book Collection in the collections panel- and experiment with the copy.

1. Top Menu: Edit > Select all Text Cells (or Ctrl+Alt+A), then reset the font in the Text Panel using a commonly used font that Lightroom-Classic lists (not Times New Roman) and reasonable text size. Also change all the text to one font, then change it back to another. ie. two changes to the font (globally)- this may be helpful. Using multiple font types in the book- I suggest not doing that.

2. For problem images, Open the problem page image, go back to Library, create a virtual copy, use the VC to replace the problem image. (See Notes below to 'find' a problem page)

3. Check that any text boxes do not have text that exceeds the available size of the text box. ie. some of the text has disappeared from the text cell. Lightroom will not 'carry-over' text to the next cell like some publishing programs but simply does not show the words that exceed the cell size. (This will error).

4. Check all Photo Cells for ‘padding’-  If on any page you increase the padding of a photo cell so that the main photo is shrunk to nothing to show just the faded background of the Photo Cell, you will have the error while saving it to pdf or uploading a book to Blurb.  Delete a Photo cell if you do not want to show a photo in a location on a page.

5. Problems with using 'Background' images appear in forum threads- try unchecking any use of background images both on the cover and Globally within the book pages.

6. Confirm that any photo you use in the book does actually exist and is available on the hard-drive. ie. not "Missing". (In Library- Right-click and "Show in Explorer/Finder" to confirm,)

7. Top Menu: Edit > Book Preferences > place a check mark in-  "Constrain Captions to text safe areas"

8. Error messages that indicate images have "transparency" can be ignored. Not a problem even if error messages suggest "Transparency". Transparent areas in images (eg. PNG files, merged panorama edges, images transformed without a constrained crop) will autofill with white.

9. Always test your book design by an Export to PDF by 'sending' it to a local PDF file before an upload to Blurb. Understand that Blurb can only receive a book that can successfully be “saved as PDF” without generating an error message. If you are building a large or detailed book in Lightroom, it is a good idea to “test” the ability to save it as a local PDF a few times while you are building the book. That way you will discover a problem early, when the problem is easier to find and fix.

    

Notes-

Keep a record of the fonts you plan to use, and make sure you follow that plan as you build your book. Feel free to change your plan, but it is a good idea to test all new fonts.

Testing Fonts- Create a test book with a few sample pages with the fonts you plan to use, and make sure the test book can successfully be saved as a PDF without generating an error message. This verifies that the fonts you plan to use are compatible.

If you get an error in your book, you can find the page that contains incompatible text font  by clicking on the progress bar on the upper left while you are saving to PDF. An information box appears, showing the pages saved from front to back. Waiting for this is tedious, but it will show you the page that is trying to be saved when the incompatible font is encountered.

Go to that page in your book (and perhaps the pages before and after, just to be sure) and look for the offending font. Here’s how to find it:

-Look at the page text and photo text (and text boxes on page templates that include text boxes).

-Select all the text in these areas to ensure that all the fonts are compatible, and that no incompatible fonts have found their way into your text.

Empty text boxes can generate this error message if they are formatted to use an incompatible font. Remove any page and photo text that is empty.