Problem with epub exported from InDesign 2023

[rebeccab38852303]

My epub goes into Kindle just fine, but when I try to upload to Ingram, it is giving me a long list of error messages saying the language is not included like this:

(RSC-005): /OEBPS/Title.xhtml: Error while parsing file: value of attribute "lang" is invalid; must be an RFC 3066 language identifier

(RSC-005): /OEBPS/Title.xhtml: Error while parsing file: value of attribute "lang" is invalid; must be an RFC 3066 language identifier

(RSC-005): /OEBPS/Title.xhtml: Error while parsing file: value of attribute "lang" is invalid; must be an RFC 3066 language identifier

(RSC-005): /OEBPS/Title.xhtml: Error while parsing file: value of attribute "lang" is invalid; must be an RFC 3066 language identifier

I exported the epub from Adobe InDesign 2023. I double checked and all my documents are set to English US, which is my default. This is the first one I’ve exported from Adobe 2023 – the others were from 2022 or earlier and I never had a problem.

Help!

Rebecca Bynum

[kglad]

in the future, to find the best place to post your message, use the list here, https://community.adobe.com/

<moved from using the community>

[rebeccab38852303]

Okay - thank you.

[James Gifford—NitroPress · Accepted solution]

This is a change in ID 2023. It adds a language tag to almost every text line.

The error results are vexing, to say the least. The tag is correctly formed and used, by EPUB standards. The 'gold standard' validator epubcheck has no problem with it. No validation should mind "extra" tags — ones with default, null or superfluous content. As you found, KDP doesn't mind them at all.

But alla sudden several publishing portals are throwing not just warnings, but fatal errors over them. The problem really lies with the inaccurate/incomplete validation at their end, but as those faults aren't likely to be fixed, Adobe really needs to revert to the last export model and not embed those tags... yet, anyway.

The only solution is to back up to ID 2022 and export your EPUB. I'm going to file a critical feature fix over in requests.

Please vote here!

[rebeccab38852303]

Thank you very much. That worked, but it was a real pain. I hope this is fixed before I finish my next book which is already started in InDesign 2023. 

[James Gifford—NitroPress]

Yeah, fortunately for you, this has already come up once or twice since the release of 2023, so I immediately knew what to suggest.

It's all a little puzzling. As EPUB exports weren't touched in any other way (unless I've overlooked something), just adding this largely null/redundant tag for standards compliance is odd... and that the actual error seems to be that the tag values are incorrectly formed, it looks as if more review or testing was in order.

Anyway, there are two fixes: change the tags for compliant form, or back out this tag addition for the time being. Hopefully the devs will choose one quickly.

[rebeccab38852303]

Thank you very much. I really appreciate your time and effort in helping me.

Blessings, Rebecca