Guides

Short answers to file problems our tools check for: what the error means, how to fix it by hand, and when a tool can help.

• “Validating h5p package failed. Missing required library”: what it means and how to fix it

  Why H5P says a library is missing when you upload a .h5p file to Moodle, WordPress or Drupal, how to tell whether the file or the site is at fault, and what to do about each.

• Adding PDF/UA tags to PDFs made with WeasyPrint

  Why WeasyPrint PDFs fail accessibility checks, when WeasyPrint's own PDF/UA option is enough, and how to tag PDFs that are already made.