EPUB FixerKDP upload error scanner

EPUB error guide

nav.xhtml not declared in the OPF manifest

Use this when nav.xhtml exists in the EPUB but content.opf does not declare it correctly. Check the OPF manifest before changing the table of contents.

Scan EPUB structureSee an example report

Scan the EPUB to check file paths and see what can be repaired or needs manual review. Your original EPUB stays unchanged.

No signup before the scan report.Your original file is not overwritten.Repair download only after EPUBCheck passes again.

Need fixed-layout, DRM, or source-file help? Check unsupported or review-first EPUB cases.

Match these report titles

  • nav.xhtml not declared in the OPF manifest
  • Navigation document missing properties nav
  • EPUB nav file exists but is not declared
  • content.opf missing nav manifest item

Start here

Confirm the nav file before editing TOC content.

This is a wiring problem when the navigation file exists but the OPF package does not mark it as the EPUB nav document.

Matched

What it means

The EPUB contains a navigation file, but content.opf does not identify it as the official EPUB navigation document.

Matched

Can it be fixed automatically?

It can be repaired when one packaged XHTML file is clearly the navigation document and its links are valid.

Matched

What to check next

Find nav.xhtml or another XHTML navigation file inside the EPUB.

Matched

What not to assume

It is unsafe when several files could be navigation, when nav links are stale, or when the TOC structure needs author judgment.

1. Example report output

What a nav declaration report should show.

The report should show whether nav.xhtml is missing, undeclared, or declared without the nav property.

Validator message

The EPUB navigation document is not declared in the OPF manifest.

Affected file

OEBPS/content.opf.

EPUB Fixer report

OEBPS/nav.xhtml exists and contains a TOC, but the manifest item lacks properties="nav".

Do this next

Add or correct the nav manifest item only if that file is the real navigation document.

Do not do this

Do not tag a chapter XHTML file as nav just to satisfy validation.

Safe repair means declaring the existing navigation document, not rewriting the TOC structure by guess.

2. Next step

Find the real navigation file.

The fix is small only when the package already contains a valid nav document.

Scan first

Find candidate nav files.

Search for XHTML files with nav or toc semantics and compare their links.

Safe repair

One nav document is obvious.

Add properties="nav" to the correct manifest item or create the missing manifest item.

Manual review

Several XHTML files look plausible.

Stop when choosing the nav document would require TOC or chapter-structure judgment.

3. Concrete path example

A typical disconnected nav.xhtml.

The file exists, but content.opf does not identify it as navigation.

Report:
Packaged file: OEBPS/nav.xhtml
Manifest item: id="nav" href="nav.xhtml" media-type="application/xhtml+xml"
properties: missing
Problem: nav.xhtml is not marked as the EPUB navigation document
Fix decision: safe if nav.xhtml is the only valid TOC document
After: add properties="nav", then validate again

If two files both look like navigation, review manually before changing the OPF.

Quick decision

Declare only the actual navigation document.

The nav property tells reading systems where the EPUB 3 table of contents lives.

Scan first

Match file, manifest item, and TOC content.

Check that the file exists, is XHTML, and actually contains the book navigation.

Safe fix

One nav file is clear.

Correct the manifest entry and nav property, then validate links inside the nav file.

Stop

The TOC file is ambiguous.

Do not choose between several possible navigation files automatically.

Common situations

Common nav declaration cases.

The file is often present, but an export or edit disconnected it from content.opf.

properties="nav" was removed.

The nav manifest item exists but no longer marks the navigation document.

Restore the property if the file is clearly nav.xhtml.

nav.xhtml is packaged but not in the manifest.

The file exists in the ZIP but content.opf does not list it.

Add the manifest item only if links and media type are valid.

A source tool created a different nav path.

Navigation may live under Text/nav.xhtml or OPS/nav.xhtml.

Use the exact packaged path, not a guessed default.

The nav file links to old chapters.

The declaration may be fixable, but the TOC links still need review.

Validate nav targets before retrying KDP.

nav.xhtml declaration error text

nav.xhtml not declared in the OPF manifest / navigation document missing properties="nav".

Where OPF nav declaration errors appear

EPUBCheck, KDP, or Kindle Previewer sees a navigation problem even though a nav.xhtml file may be inside the EPUB.

What it means

The nav file is present but not connected to the package manifest.

The OPF manifest item may be missing, have the wrong href, use the wrong media type, or lack properties="nav".

Before you edit

Check the nav manifest item and properties value.

A safe fix needs one real nav document. Do not mark a random XHTML file as nav just because it has links.

  1. 1Find nav.xhtml or another XHTML navigation file inside the EPUB.
  2. 2Open content.opf and check whether the file appears in the manifest.
  3. 3Confirm the manifest item uses media-type="application/xhtml+xml".
  4. 4Check whether the manifest item has properties="nav".
  5. 5Validate that the nav links point to real chapter files and anchors.

Why KDP checks it

Why validators require properties="nav".

EPUB 3.3 package rules

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

EPUBCheck checks EPUB 2 and EPUB 3 files against the official rules and reports package, markup, link, and file-reference problems.

KDP eBook file formats

KDP supports EPUB files that meet Kindle Publishing Guidelines and recommends checking the file with Kindle Previewer before upload.

Repair example

When nav.xhtml declaration can be repaired safely.

Before / after example

Before: nav.xhtml exists but the OPF manifest does not mark it as nav. After: the correct manifest item has properties="nav" and the EPUB validates again.

Ready to retry?

Scan the OPF manifest before editing nav.xhtml.

Upload the EPUB that failed. The report should show the nav file path, manifest item, media type, and properties value.

Upload EPUB to scan

FAQ

Questions authors ask about nav.xhtml declaration.

What does properties="nav" do?

It tells EPUB 3 reading systems which manifest item is the navigation document for the book.

Can EPUB Fixer add properties="nav"?

It can be safe when one XHTML file is clearly the navigation document and its links are valid.

Is this the same as missing nav.xhtml?

No. Here the nav file may exist but is not declared correctly. A missing nav.xhtml error means the file itself may be absent.

Should I edit the TOC entries too?

Only if the scan shows broken targets. Declaration fixes and TOC content fixes are separate decisions.

Related EPUB error guides