# EPUBCheck OPF-044: fallback has no XHTML, how to fix it

Source: https://epubcc.com/epubcheck/opf-044/ (updated 2026-11-04)

EPUBCheck OPF-044 is an error message: “Spine item with non-standard media-type "…" has no EPUB content document fallback.” A spine item of a non-standard media type has a fallback chain, but no item in that chain is an EPUB content document. EPUB requires every spine fallback chain to end in a document reading apps can always show.

- Official message (EPUBCheck 5.4.0): Spine item with non-standard media-type "%1$s" has no EPUB content document fallback.
- Default severity: Error

## Typical causes

- A fallback that points to another foreign file, such as one image format falling back to another.
- The XHTML fallback at the end of the chain was removed.
- A fallback chain that ends at a file with a mistyped media type.

## How to fix it

1. Follow the fallback attributes from the item EPUBCheck names.
2. Add an XHTML document with equivalent content and make the chain reach it.
3. Or replace the spine item with that XHTML document and drop the chain.

## When it's not this

If the spine item has no fallback attribute at all, that is OPF-043.

## Sources

- EPUB 3.3, §3.5.1 Manifest fallbacks: https://www.w3.org/TR/epub-33/#sec-manifest-fallbacks (read 2026-11-04)

Message text and severity: EPUBCheck (W3C, BSD-3-Clause). Explanation: EpubCC.