Back to Error DirectoryW3C EPUBCheck & Apple Books
CSS-008Retailer Warning

Disallowed or Deprecated CSS Property in Stylesheet

A stylesheet includes proprietary or unsupported CSS properties.

Automated 1-Click Fix Ready

Fix all CSS-008 errors in your EPUB automatically

PreFlight cleanses stylesheet files by purging deprecated vendor prefixes and Word export artifacts while keeping your typography intact.

Scan & Fix Now

What This Error Means in Plain English

Exporting books from Microsoft Word or Adobe InDesign often leaves messy proprietary CSS properties (e.g. -mso-*, position: fixed, or unsupported absolute coordinates) that cause broken text overlap on Kindle and Kobo.

Why Retailers & EAA Regulations Block This File

Causes visual rendering glitches across varying e-reader font sizes and screen dimensions.

Technical Specification: EPUB 3 defines an EPUB Style Sheets profile based on CSS 2.1 and specific CSS3 modules. Properties that break pagination flow are flagged.

Manual Fix Instructions (for Sigil / Calibre)

  1. Open your book's .css files.
  2. Search for and remove Microsoft Word style bloat (mso-*, line-height absolute points, fixed positions).
  3. Use relative units (em, rem, %) for fluid typography.