# EPUBCheck RSC-030: file URL not allowed, how to fix it

Source: https://epubcc.com/epubcheck/rsc-030/ (updated 2026-11-04)

EPUBCheck RSC-030 is an error message: “File URLs are not allowed in EPUB, but found "…".” A file: URL points to a file on someone's computer; EPUB does not allow file URLs. Readers cannot reach the author's disk, so the link or image is broken for everyone.

- Official message (EPUBCheck 5.4.0): File URLs are not allowed in EPUB, but found "%1$s".
- Default severity: Error

## Typical causes

- Links or images that still point to the author's disk, such as file:///C:/Users/… after export.
- Documents exported from a word processor that stored absolute local paths.

## How to fix it

1. Find the file: URL named in the message.
2. Copy the resource into the book folder, add it to the manifest and reference it by a relative path, or remove the reference.
3. Validate again.

## When it's not this

An http or https URL to a resource that must be inside the EPUB is RSC-006.

## Sources

- EPUB 3.3, §3.8 File URLs: https://www.w3.org/TR/epub-33/#sec-file-urls (read 2026-11-04)

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