Understanding EPUB validation
What to do if your EPUB does not pass validation
The EPUB3 files that CircularFLO produces can be validated automatically as part of the process. We use the free tool pagina EPUB-Checker to do this.
As the creation process with CircularFLO is automatic it is rare that an EPUB will not validate but if it does then you will be alerted and the report will be shown in EPUB-Checker.
The most common issue is a broken hyperlink. Check the report to see if a ‘required elements missing’ error is caused by hyperlinks pointing to badly formatted URL or a non-existent page.
Even if the issue is not a missing or broken link, there is usually a simple reason but unfortunately the simple reason might be hidden in a scary looking report!
This site helps to decipher what the report means.
If you are having trouble understanding a EPUB check report then please feel free to send the EPUB and the report to us.
