All files are required to be checked and should pass ePub Checker.
If you're having technical issues with getting a valid ePub please contact a fellow team member, send out a team email seeking help/advise or send out a message on Slack.
At current time of writing ePub Checker integrates epubcheck-3.0.1.jar and epubcheck-4.0.2.jar.
Many times we get asked why do we still incorporate/check with epubcheck-3.0.1.jar and the simplest answer is channels we submit titles to still validate with this JAR. For a few months we only validated with epubcheck 4.0.2 when but we received channel declines and had to further test and due to these issues it was re-integrated back into the app.
If you want to do isolation epubcheck testing:
- epub-checker-3.app: uses epubcheck-3.0.1.jar only.
- epub-checker-4.app: uses epubcheck-4.0.2.jar only.
Please note there is no support for the above two mentioned apps.
In the future, hopefully within 2021 will be moving all validation from AppleScript or Bash to solely Node. It has been noted that w3c has released a new version (v4.2.4) and this planned for the new app.