Back to Error DirectoryW3C EPUBCheck Standard
MED-013Retailer Warning

Media Overlay Document referenced from the "media-overlay" attribut...

Media Overlay Document referenced from the "media-overlay" attribute does not contain a reference to this Content Document.

Automated 1-Click Fix Ready

Fix all MED-013 errors in your EPUB automatically

PreFlight checks for MED-013 issues in memory and provides 1-click remediation during client-side packaging.

Scan & Fix Now

What This Error Means in Plain English

EPUBCheck detected Media Overlay Document referenced from the "media-overlay" attribute does not contain a reference to this Content Document.. Digital reading systems and bookstores require standard conformance to ensure compatibility across all reading apps.

Why Retailers & EAA Regulations Block This File

Automated book distributors (Apple Books, Amazon KDP, Kobo, and IngramSpark) run strict EPUBCheck validation on ingest and reject non-compliant files.

Technical Specification: W3C EPUBCheck rule MED-013: Media Overlay Document referenced from the "media-overlay" attribute does not contain a reference to this Content Document.

Manual Fix Instructions (for Sigil / Calibre)

  1. Locate the file and line flagged under rule MED-013 in your EPUB editor (Sigil or Calibre).
  2. Apply the required syntax correction matching the MED-013 specification.
  3. Re-pack and validate with PreFlight EPUB to confirm zero residual errors.