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Troubleshooting

Common EPUB upload errors and how to fix them

Most EPUB upload errors are easy fixes: invalid markup, missing navigation, bad cover references, or remote resources. Here's how to clear the common ones.

Last updated 2026-06-15

Most EPUB errors come from a handful of common causes — and Chiify auto-fixes many of them for you. Here is what the frequent ones mean and how to clear them.

Chiify fixes a lot automatically

On upload, Chiify runs EPUBCheck, auto-heals common structural problems, and upgrades EPUB 2 to EPUB 3 during delivery. So some issues never reach you. When one does, here is the playbook.

Frequent errors

  • Missing navigation / table of contents. Your EPUB needs a clickable nav. The simplest fix is to upload your DOCX and let Chiify build a clean EPUB with proper navigation — see clickable table of contents.
  • Embedded cover not found or not an image. The cover inside the file is broken; re-upload and let Chiify inject the cover. See cover upload errors.
  • Remote resources / external links to fonts or styles. EPUBs must be self-contained. Chiify strips offending remote references during healing; if it persists, rebuild from DOCX.
  • Invalid markup (bad attribute, invalid id, src not a URI). These come from messy export tools. The reliable fix is to re-upload the DOCX for a fresh, valid conversion.
  • Placeholder text detected. Not a format error — remove template/boilerplate text. See why was my book blocked.

The one fix that solves most cases

When in doubt, upload your Word DOCX instead of a hand-made EPUB. Chiify's free conversion produces a valid EPUB 3 that passes validation cleanly.

Still need help? Open a ticket from your dashboard or email [email protected] — a real person replies.

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