Error in Epub - indesign I have received back from my team and don't understand

Report · Feb 21, 2024

Hi,

I have an issue with a fixed layout epub, my team reported back to me this error when trying to upload it. This is a first time that it has popped up and I don't know what it means. Has anyone ever had this and how can I fix it?

" PKG-026: Obfuscated resource must be a Font Core Media Type (was declared as "application/x-font-ttf" in "OEBPS/content.opf").META-INF/encryption.xml L5 META-INF/encryption.xml L23 "

screenshot here :

Report · Apr 11, 2025

Sure! The thing you want to do is to open up the EPUB in Sigil or similar text editing software. Then, open the content.opf file, search for media-type="font/ttf" and change that to media-type="application/vnd.ms-opentype". Please let me know (email: laura (at) bradytypesetting (dot) com) if you need any further support.

Report · Jul 08, 2025

Thank you, Laura. What a valuable hint. This work-around worked instantly for me and without much effort. I added it to my epub checklist. 🙏

Report · Apr 02, 2025

Did you get a workable solution to this because a year later and I am having the same problem?!!!!

Thanks

Report · Apr 02, 2025

Run your EPUB past the most current version of EPUBchecker — NOT any wrapped, app'ed or commercialized version. If it passes the latest version, the problem is not yours. But it's hard to do anything about sales/distribution portals that are still running older versions of validation.

The EPUB 'industry' being perpetually out of step with each other is one of its more persistent and aggravating problems.

Report · Apr 03, 2025

Thanks James. I will give that a go. I have raised it with Ingramspark... no reply (meh!)