# EPUBCheck PKG-020: package document not found, how to fix it

Source: https://epubcc.com/epubcheck/pkg-020/ (updated 2026-11-04)

EPUBCheck PKG-020 is an error message: “OPF file "…" could not be found.” The package document (OPF) named in META-INF/container.xml does not exist at that path. Without the package document, neither reading apps nor EPUBCheck know which files make up the book.

- Official message (EPUBCheck 5.4.0): OPF file "%1$s" could not be found.
- Default severity: Error

## Typical causes

- The full-path attribute of the rootfile element has a typo or the wrong case: paths are case-sensitive.
- The package document was renamed or moved (for example from OEBPS/ to EPUB/) without updating container.xml.
- The package document was left out when the archive was built.

## How to fix it

1. Open META-INF/container.xml and read the full-path value of the rootfile element.
2. Make it match the real path of the .opf file, relative to the root of the archive, for example full-path="OEBPS/content.opf".
3. Rebuild the archive and validate again.

## When it's not this

If container.xml itself is missing, that is RSC-002; if no rootfile has the right media type, RSC-003.

## Sources

- EPUB 3.3, §4.2.6.3.1.3 The rootfile element: https://www.w3.org/TR/epub-33/#sec-container.xml-rootfile-elem (read 2026-11-04)

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