# EPUBCheck RSC-003: No rootfile tag with media type…

Source: https://epublab.com/epubcheck/rsc-003/ (updated 2026-11-03)

EPUBCheck RSC-003 is an error message: “No rootfile tag with media type "application/oebps-package+xml" was found in the container.” META-INF/container.xml exists but none of its rootfile elements has the media type application/oebps-package+xml, so the package document cannot be found.

- Official message (EPUBCheck 5.4.0): No rootfile tag with media type "application/oebps-package+xml" was found in the container.
- Default severity: Error

## Typical causes

- A misspelled or missing media-type attribute on the rootfile element.

## How to fix it

- Set media-type="application/oebps-package+xml" on the rootfile element that points to the package document.

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