Back to Error DirectoryW3C EPUBCheck Standard
OBS-001.elementRetailer Warning

the resource element

the resource element

Automated 1-Click Fix Ready

Fix all OBS-001.element errors in your EPUB automatically

PreFlight checks for OBS-001.element issues in memory and provides 1-click remediation during client-side packaging.

Scan & Fix Now

What This Error Means in Plain English

EPUBCheck detected the resource element. 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 OBS-001.element: the resource element

Manual Fix Instructions (for Sigil / Calibre)

  1. Locate the file and line flagged under rule OBS-001.element in your EPUB editor (Sigil or Calibre).
  2. Apply the required syntax correction matching the OBS-001.element specification.
  3. Re-pack and validate with PreFlight EPUB to confirm zero residual errors.