# EPUBCheck PKG-027: Could not extract EPUB ZIP content…

Source: https://epublab.com/epubcheck/pkg-027/ (updated 2026-11-03)

EPUBCheck PKG-027 is a fatal error message: “Could not extract EPUB ZIP content, probably due to file names not encoded in UTF-8.” EPUBCheck could not extract the archive, most likely because the file names inside the ZIP are not encoded in UTF-8.

- Official message (EPUBCheck 5.4.0): Could not extract EPUB ZIP content, probably due to file names not encoded in UTF-8.
- Default severity: Fatal error

## Typical causes

- A ZIP created by an old tool or on a system that stores file names in a local code page, often with accented characters in the names.

## How to fix it

- Rename files to ASCII names, or rebuild the archive with a tool that stores names in UTF-8.
- Rebuild the archive with the mimetype file first and stored uncompressed, for example from the folder that contains the book: zip -X0 book.epub mimetype and then zip -rX9 book.epub META-INF OEBPS (use your own folder names).

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