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

[Audrey28641613b1ak]

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 :

 

[Robert at ID-Tasker]

Have you tried Google?? 

https://code-interactive.com/2023/04/obfuscated-resource-must-be-a-font-core-media-type-error-from-i... 

[James Gifford—NitroPress]

You have a bad font — bad for EPUB embedding/encryption. There are few solutions except replacing it with a font that is compatible/licensed for e-book export.

[Laura Brady]

It is not a bad font; it's related to the media type and is easily fixed. 

[James Gifford—NitroPress]

Bad as in "not compatible with the format, process or goal." It may well be technically perfect, but not within the narrow range of type, format, model or licensing EPUB demands.

[Kev5C3A]

I had this problem when I tried to upload the ebook to IngramSpark.

Using Calibre, I converted the epub into an epub (yes, the same file format) and that fixed the problem.

[James Gifford—NitroPress]

This is an interesting approach, and of course in line with the routines for fixing corrupted InDesign and Word files. It depends, however, on the reliability of Calibre to write/rewrite code, not only for technical compliance but preserving anything outside standard, vanilla layout. I'd see it as more of a bandaid/hack than a proper approach, that of finding the actual cause of the fault and fixing it.

(I profess to be a bit baffled by the "e-book conversion" boffins. When format conversion isn't something verging on piracy, it seems unnecessary to me to convert the same book to read on different readers... but it is or was quite the active segment of the reader/collector/hacker area of the field.)

[Kev5C3A]

I actually think (in my case) the problem is IngramSpark's.

We have a professional ebook converter (and I used to convert ebooks in the day when they were written in code from scratch).

The ebook uploads fine on Amazon KDP, and various ebook readers (like Kindle, iBooks, Calbre's own reader) have no problem withit. (iBook's is actually a good test of coding -- if there's a problem, it'll complain as you're going through the book on the page with the issue.) But IngramSpark flagged it.

In the past, I've found IngramSpark flag things that these other platforms don't. Also, often it flags things that are redundant, e.g. a tag that's not closed in the code, even though that has no bearing on how the ebook functions.

Interestingly, when I went into Calbre's ebook editor and used its automated fix, it broke more things as far as IngramSpark were concerned, e.g. whereas IngramSpark flagged three things previously, now it was flagging twelve.

But using Calibre's converter (converting it from epub to epub) fixed it for uploading on IngramSpark.

I'm guessing the conversion is just embedding the font in a way that's satisfying IngramSpark's internal evaluation.

[James Gifford—NitroPress]

Yes, Ingram often seems to be the most stringent vendor, more or less in step with every warning and info report EPUBcheck generates, but unforgiving about any of them.

The real solution here is not to embed fonts in EPUB. It brings little to most books, it's wholly dependent on reader and user choices anyway, it bloats file sizes and — all too often — it simply brings more convoluted trouble than any jot of esthetic improvement.

To me, it's part of "respect the medium" to not try to force print-like control on e-books. If you're obsessed with presenting a page 'just so' — use PDF.

[Laura Brady]

This is a known issue and is related to TTF fonts. When you export from InDesign they come out with "application/x-font-ttf" in the manifest. If you change that to "application/vnd.ms-opentype" your fonts will still work just fine and you won't have a validation error.