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EPUBCheck · Navigation document

NAV-001

Updated:

EPUBCheck NAV-001 is an error message: “The nav file is not supported for EPUB v2.” An EPUB 2 publication includes an EPUB 3 navigation document, which EPUB 2 does not support.

The official message

The nav file is not supported for EPUB v2.

Default severity
Error. The EPUB breaks a rule of the specification and is invalid. Stores and Send to Kindle may reject it, and EPUBCheck exits with status 1.
EPUBCheck version
5.4.0

Typical causes

  • A package with version="2.0" that contains a nav document, often after partial conversion to EPUB 3.

How to fix it

  • Upgrade the whole package to EPUB 3 (version="3.0" and the required metadata), or remove the nav document and keep the NCX.

Terms used here

Other NAV messages

  • NAV-003 The Navigation Document must have a page list when content document(s) contain page breaks (epub:type="pagebreak").
  • NAV-010 "…" nav must not link to remote resources; found link to "…".
  • NAV-011 "…" nav must be in reading order; link target "…" is before the previous link’s target in … order.

Message text and severity from EPUBCheck 5.4.0 (W3C, BSD-3-Clause). Explanation by EPUBLab.

FAQ

What does EPUBCheck NAV-001 mean?

EPUBCheck NAV-001 is an error message: “The nav file is not supported for EPUB v2.” An EPUB 2 publication includes an EPUB 3 navigation document, which EPUB 2 does not support.

Is NAV-001 an error?

NAV-001 is reported as error by default. The EPUB breaks a rule of the specification and is invalid. Stores and Send to Kindle may reject it, and EPUBCheck exits with status 1.