epub validation error

[detritus books]

So I just exported this EPUB, and then did the "validation" process on it in Sigil, and got this error message:

Error OPF bad item media type value : The <item> element's "media-type" attribute has value "application/vnd.ms-opentype", but the file's media type is "application/x-font-ttf". near column 105

How would I fix this?

[detritus books]

Nobody?

[Derek Cross]

Which version of InDesign and OS?

Reflowable text ePub or FXL ePub?

Crack open the ePub and have a look at the OPF – What’s in an ePUB?: The OPF File – eBOUND Canada

IMO Flightdeck is easily the best validator worth $15 for a month's worth. https://www.ebookflightdeck.com/

[detritus books]

Mac OS High Sierra 10.13.3

InDesign CC 2017.1

Reflowable

Thanks!

[detritus books]

Does that information help with what to do about this at all?

[detritus books]

Is it possible this is an embedded font issue? I never embed fonts, I don't even know how, but maybe it happened on accident?

[Derek Cross]

It’s generally thought best to use OTF fonts - also all Typekit fonts are licensed. for ePub

Did you use the Flightdeck validator, if you don’t want to spend the money there’s a free one but it doesn‘t give as much information: EPUB Validator (beta)

By the way have you viewed the ePub on any ePub reading software or devices to see if it works or there's any issues?

[detritus books]

Oh, I never heard the thing about .otf for epub. Why is that?

I used the validator in Sigil called FlightCrew.

I didn't see any issues in iBook, but haven't tried it in Calibre yet. I generally go iBook > Sigil > Calibre

[Derek Cross]

OTF = OpenType Font

How does your ePub look in Adobe Digital Editions Adobe Digital Editions | Download

Ensure you've exported it from InDesign as ePub version 3.

[detritus books]

I know what OTF stands for, I just don't know why it would be preferred for epub?

[Derek Cross]

You can use TrueType and OTF, fonts but Postscript Type 1 cannot be embedded in an ePub.

Try exporting your ePub without embedding the fonts and see if the validator throws up any issues.

[detritus books]

I actually couldn't find the part in the dialog about embedding fonts. But, I did set it to epub 3 (it was set at 2.0.1 or whatever) and then Sigil failed to validate, but the online validator you posted gave it back with no errors so I guess it's good now. Thanks!

[Derek Cross]

Good to hear.

I inadvertently seem to have added a link to system requirements to my reply – sorry about that!

[detritus books]

Ha, I was a little confused about that link!