It has the same warning each time but the line & column numbers are different for each chapter. We only see it happen on an iPad (related to Apple books perhaps), but other ePubs look fine.
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.”
Thanks for your reply. Unfortunately, I’m still getting the “error on line 12 at column 215” message in Chapter 1. However, I no longer see that error in any of the other chapters. I looked at the tags in the code and found the following invalid tag at the very beginning:
. I removed the tag, but alas, it didn’t do anything to fix the issue.
Hi Mark! I’d suggest deleting the EPUB files from your computer and iBooks library. Then, export a new EPUB file and open it in iBooks. Sometimes an older file might mean that you’re seeing a cached display, so deleting the files first will confirm that you’re looking at the newest version.
Thanks for the suggestion–turns out the tag tag was reinserted in the title without my knowledge. That’s why the error message reappeared. We were using the tag to format the chapter title which needed a line break in the middle. The fix was to simply insert a slash mark to close the tag as follows: . Apparently the EPUB export follows XHTML or XML where different rules make the tag is invalid and even empty tags like must be self-closed. Hence for the EPUB only the is used. This rule doesn’t apply to other formats, however. Thanks for your help with this.