# EPUBCheck RSC-016: Fatal Error while parsing file: …

Source: https://epublab.com/epubcheck/rsc-016/ (updated 2026-11-03)

EPUBCheck RSC-016 is a fatal error message: “Fatal Error while parsing file: ….” A file is not well-formed XML, so it cannot be parsed at all. EPUB content documents must be valid XML.

- Official message (EPUBCheck 5.4.0): Fatal Error while parsing file: %1$s
- Default severity: Fatal error

## Typical causes

- An unescaped & in text or in a URL (it must be written &).
- HTML named entities such as   that XML does not define.
- Unclosed or mismatched tags, or an attribute without quotes.

## How to fix it

- Read the text after the colon: EPUBCheck reports the file, the line and column, and the parser's own description of the problem.
- Escape & as &, replace named entities with numeric ones (  for a non-breaking space), and close every tag.

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