Match the report title.
Look for "EPUB missing nav document" or the closest title above. Keep the original EPUBCheck, KDP, or Kindle Previewer wording if it differs.
EPUB error guide
Use this when EPUBCheck, KDP, or Kindle Previewer says the EPUB navigation document is missing. Check nav.xhtml, the OPF manifest, and the spine before rebuilding the TOC.
You see
Choose this guide when your KDP, Kindle Previewer, or EPUBCheck wording matches "EPUB missing nav document" or a close variant.
You get
The report points to the package, OPF, nav, XHTML, resource, anchor, metadata, or ZIP area behind the message.
Do not upload
Use the source tool or publishing workflow for DOCX, PDF, KPF, fixed-layout, DRM, cover design, KDP listing, or review problems.
Scan when the message does not name the affected path. The report shows affected paths and repair decisions, not manuscript text.
Need fixed-layout, DRM, or source-file help? Check unsupported or review-first EPUB cases.
Match these report titles
Use this guide when
Your message matches "EPUB missing nav document" or one of the report titles above.
Upload if
You have the exported reflowable .epub and need the affected path, file, field, or repair decision before editing.
Handle outside this tool
Use the source tool or publishing workflow for DOCX, PDF, KPF, KCB, fixed-layout, comics, image-first books, DRM, visual design, or KDP listing and approval problems.
Read the scan report
Use the report label, affected file, and repair decision together. A matching title alone is not enough if the file path or EPUB structure points to a different problem.
A useful report does not stop at the error name. It connects the message to an internal file and a next action.
Look for "EPUB missing nav document" or the closest title above. Keep the original EPUBCheck, KDP, or Kindle Previewer wording if it differs.
Use the Affected area, Source file, Target file, or Problem type rows before editing OPF, nav, XHTML, CSS, or image paths.
Repairable means one clear structural change. Needs review or Not supported means use the named file, source project, or platform step.
Copy these fields from the report instead of rebuilding the fix from memory.
1. Example report output
The report should distinguish a missing file from a file that exists but is not declared.
Validator message
The EPUB 3 navigation document is missing.
Affected area
content.opf manifest and nav.xhtml path.
EPUB Fixer report
No manifest item has properties="nav" and no nav.xhtml file is packaged.
Do this next
Generate a flat nav only when the spine order and every reading-order page title are unambiguous.
Do not do this
Do not create a table of contents from random file order or decorative headings.
Safe repair requires one existing nav file to reconnect, or a complete spine with one unambiguous title for every page so a flat nav can be generated without inventing hierarchy.
2. Next step
Those two cases need different fixes.
Scan first
Check whether nav.xhtml exists under a different folder, name, or case.
Safe repair
Declare or reconnect the existing nav file when it is clearly the intended navigation document.
Generate or review
Generate a flat nav only when spine order and every page title are unambiguous. Return to the source tool when titles, hierarchy, or reading order need choices.
3. Concrete path example
The OPF points to no EPUB 3 navigation document.
Validator: EPUB 3 navigation document is missing. Report: content.opf manifest properties="nav": not found Packaged nav.xhtml: not found toc.ncx: present Fix decision: generate a flat nav only if spine order and every page title are unambiguous After: add the flat nav and OPF wiring, then validate again
If only toc.ncx exists, do not assume it is enough for EPUB 3 platform expectations.
Quick decision
A navigation document is user-facing, so wrong entries can make the book harder to use even if validation passes.
Scan first
Search for nav.xhtml, toc.ncx, and OPF manifest properties before editing.
Safe fix
Reconnect or declare the navigation file when the target is obvious.
Stop
Do not guess titles, hierarchy, or chapter boundaries from weak file names.
Start here
EPUB 3 uses a navigation document, often nav.xhtml, so reading systems can expose the table of contents. A missing nav file can make KDP reject a book even when chapters exist.
The EPUB does not expose the navigation file that tells readers and publishing systems where the table of contents lives.
It can be repaired when one valid navigation file already exists, or when a flat nav can be generated from the existing OPF spine and one unambiguous title for every reading-order page.
Search the EPUB for nav.xhtml or another XHTML file that contains epub:type="toc".
It is unsafe when headings, chapter titles, hierarchy, or reading order need author judgment.
Common situations
Missing nav errors often follow export, cleanup, or EPUB 2 to EPUB 3 conversion.
The OPF and chapters remain, but the navigation file is gone.
Generate a flat nav only from a complete spine and one unambiguous title per page; otherwise regenerate from the source project.
The file may be present but not declared as the EPUB navigation document.
Reconnect it only when its contents are clearly the book TOC.
An older EPUB 2 navigation file may not satisfy EPUB 3 expectations.
Create EPUB 3 nav only when the spine order and every page title provide the exact flat entries.
The visible issue may be missing nav.xhtml rather than missing chapters.
Scan OPF and navigation wiring before rebuilding the book.
EPUB navigation document is missing / nav.xhtml is missing.
KDP, Kindle Previewer, or EPUBCheck cannot find an EPUB 3 navigation document in the package.
What it means
The EPUB does not expose the navigation file that tells readers and publishing systems where the table of contents lives.
The nav file may be missing, removed from the OPF manifest, named differently, or never generated by the export tool.
Before you edit
A safe fix needs either one real navigation file or an existing spine order with one unambiguous title for every reading-order page. Do not invent hierarchy or titles.
Why KDP checks it
The OPF file is the EPUB's map: metadata, file list, reading order, and navigation wiring. KDP and EPUBCheck use it to decide whether the book package is coherent.
EPUBCheck checks EPUB 2 and EPUB 3 files against the official rules and reports package, markup, link, and file-reference problems.
KDP supports EPUB files that meet Kindle Publishing Guidelines and recommends checking the file with Kindle Previewer before upload.
Can this be fixed safely?
It can be repaired when one valid navigation file already exists, or when a flat nav can be generated from the existing OPF spine and one unambiguous title for every reading-order page.
It is unsafe when headings, chapter titles, hierarchy, or reading order need author judgment.
Before: no nav document is declared or packaged. After: a valid nav is connected only when the intended TOC structure is clear.
Ready to retry?
Upload the EPUB that failed. The report should show whether nav.xhtml is missing, undeclared, or present under another path, and whether the spine and page titles can support deterministic flat generation.
Upload EPUB to scanFAQ
It is the EPUB 3 navigation document. It usually contains the table of contents that reading systems and publishing platforms use.
Only as a flat navigation document when the OPF spine already gives one clear reading order and every reading-order page has one unambiguous title. It does not invent hierarchy; incomplete or unclear inputs belong in the source tool.
Not always. toc.ncx is the older EPUB 2 navigation file, while EPUB 3 expects a navigation document declared in the OPF manifest.
Chapters can exist as files while the EPUB navigation layer is missing or disconnected from the package.