Hi Mark, thanks for the link and the screenshot.
I’ve taken a look, and it appears that the
tag in the title of Chapter 1 “Introduction to the Field of Community Psychology” was causing the error. Removing this tag resolved the issue, and you can confirm the same with a new export.
The error reports for the EPUB also indicated that the different weights for the PT Serif fonts were not properly loaded – perhaps you could check to see that all the custom CSS for the fonts has been correctly entered. Generally, we recommend against uploading custom fonts for e-books, as this tends to increase the file size of the book.
There were also some small error messages around glossary terms - while these did not have any impact on being able to open or view the EPUB, I’ve still reported the error to the Pressbooks support team to troubleshoot. I’ll keep you posted as I hear from them.
Please let me know if you have any more questions. I look forward to hearing a confirmation about the resolved error message “Begin Chapter Error on line 12, col. 215. Opening and ending tag mismatch.”