# EPUBCheck OPF-031: File listed in reference element in…

Source: https://epublab.com/epubcheck/opf-031/ (updated 2026-11-03)

EPUBCheck OPF-031 is an error message: “File listed in reference element in guide was not declared in OPF manifest: ….” A reference in the EPUB 2 guide element points to a file that is not in the manifest.

- Official message (EPUBCheck 5.4.0): File listed in reference element in guide was not declared in OPF manifest: %1$s.
- Default severity: Error

## Typical causes

- A guide entry left after a file was removed or renamed.

## How to fix it

- Correct the guide reference or remove it. In EPUB 3, landmarks in the navigation document replace the guide.

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