“Your EPUB is fine. Kobo disagrees. Blame Adobe.” (opens in new tab)

An infuriating story about something most of us don’t really stop to think about: e-books and the rendering engines companies and software use to display them. It’s the year 2026. Thanks to the horrendous RMSDK which Kobo decided to use as their backbone for all book rendering (probably for DRM reasons), a single line of perfectly valid CSS turns a perfectly valid EPUB file into a “corrupted file” on Kobo and just drops the whole book. No clear error message, no fallback. Just a massive fail....