# EPUBCheck OPF-065: Invalid metadata declaration, probably…

Source: https://epublab.com/epubcheck/opf-065/ (updated 2026-11-03)

EPUBCheck OPF-065 is an error message: “Invalid metadata declaration, probably due to a cycle in "refines" metadata.” Metadata refines chains loop back on themselves, so EPUBCheck cannot resolve what refines what.

- Official message (EPUBCheck 5.4.0): Invalid metadata declaration, probably due to a cycle in "refines" metadata.
- Default severity: Error

## Typical causes

- A meta element whose refines attribute points, directly or through others, back to itself.

## How to fix it

- Make every refines point to the element it describes, with no loops.

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