EPUB 2.0 Validation Error (RSC-005) with Cover Images in InDesign

[Cyrusmage]

So I'm having the worst week ever.

I have a dozen ebooks that I need to make and it looks like InDesign is throwing me a curve ball... again.

It's a list of errors with the code RSC-005.

It doesn't matter if it's a real ebook (9781761112751.epub - Yes, there is a font issue on this one too, but it doesn't matter as readers will ignore the font anyway.)

Or just a single page with lorem ipsum (Testing.epub) which I made to test whether I was the problem or InDesign was, but the results are the same. Suffice to say, it's definitely InDesign.

All of a sudden every ebook I'm exporting is failing the EPUB 2.0.1 rules because of this.

It's never happened before, I don't understand what this means.

My older ebooks were fine. They all passed validation before, but when I try exporting them now in the current version of InDesign 19.5 they all have this issue now.

I've narrowed it down to the cover images. I figured given most of the errors contain a reference to 'cover.html'.  It has something with the cover images all of a sudden.

So when I export without a cover image, lo and behold, all the 'cover.html' errors disappear, but it still fails the validation.

Can someone help me understand what is happening here? And what I can do to fix this?

I need it to export with the cover images and I can't upload these to Draft2Digital until they pass validation.

Please help!

<Title renamed by MOD>

[Vivek12]

Hi, Sorry for the trouble. Please try the steps suggested in this link and share the outcome.

^VS

[Cyrusmage]

Vivek12, thanks for replying, but the discussion you linked has no official resolution or steps to follow. There are 3 different problems raised in the comments, but none of them is like mine.

[Laura Brady · Accepted solution]

Hiya. The problem is that you are outputting EPUB 2. If you output EPUB 3 instead, you will have better results. There have been a number of improvements to how InDesign creates EPUB that are particularly impactful for accessibility which is going to negatively impact how EPUB 2 is created. <figure> is HTML 5 that's not permitted in the older EPUB 2 standard. 

[Cyrusmage]

Thanks, Laura.

Exporting in 3.0 did remove all those errors. Strange that they happened at all though.

[James Gifford—NitroPress]

You should not be using EPUB 2; it's been obsolete for a decade. Even if your validation faults can be resolved, you're all but wasting your time creating books in this outdated format.

I'd also recommend using EPUBcheck, always updated to the most current version, as your one and only validator. The others, especially those embedded in websites and even those that use EPUBcheck as their engine, are.... variable in their real-world results.

Just out of curiosity, why did you choose EPUB2?

[Cyrusmage]

Thanks for the reply, James.

I'm not super knowledgeable or confident with ebooks. I was trained by someone else to export them this way because it was how they got the ebooks to work and pass validation in the past. When I asked why we weren't using 3.0 they said 2.0 was older and more reliable. I didn't realise it was so out of date.

(Note, I just tried exporting in 3.0 and there are no errors now. Draft2Digital has accepted the file, too. Yay! I'll try this on a few more and make sure they all work, too.)

I'm not super confident with Epubcheck either.

I found it on Github and someone mentioned there was a skin? GUI? (whatever that means) called Pagina which allowed me to run Epubcheck on my desktop. I found it listed by the people running Epubcheck too. I know that doesn't always mean it's 100% right. Pagina says it's using version 5.1.0 of Epubcheck, which is the latest version on Github... so if it's not close enough, then I don't know of any other way I can verify if the Epubs are right.

My knowledge of this stuff is really limited.

Pagina was showing me the same error codes that Draft2Digital was picking up, which also runs Epubcheck, I believe, to verify/validate the epubs before it lets me publish them online.

P.S. If you know of any tutorials for making & troubleshooting ebooks that would be good to do so I can get a better understanding of this stuff, I would be grateful. I've been trying to learn more so I can make the ebooks more consistently, but I mostly deal with print media so I'm a bit out of my depth here.

[James Gifford—NitroPress]

Okay. That puts it in context. I sigh in exasperation at the vast amount of outdated, wrong, quirky and sometimes just plain goofy information passed around as gospel in the e-book continuum, especially from the faction that maintains EPUB 2 is superior because <reasons>. Unfortunately, I know of absolutely no reliable, updated, coherent, quirk-free sources of information on any part of the process; it's divided between the relatively small cadre of exactingly-techincal users (mostly at the academic level), and the teeming hordes of largely self-taught amateurs, or those taught by self-taught amateurs. You might find my book useful but it has a particular focus on doing professional work with InDesign, primarily to Kindle, and does not have any truly introductory or tutorial content outside of that. You may find the essays here of use, though: Digital Publishing Basics.

Use EPUB 3 from here on and adapt your formatting, workflow and export methods to optimize it. If you're fairly adept at getting the results you want from InDesign, my book might be just the right approach for you to improve your processes and results.

EPUBcheck is challenging to use since it's a purely command-line tool, but I remain wary of all the wrappers and UIs that "interpret" the results for you. I don't know a good in-between solution. I tend not to use or advocate use of validators per se, though; IMHO they are a highly technical tool for fine-tuning files to a usually unnecessary degree, or a holdover from the "build it from sticks and then fix all your errors" approach, which should no longer be used. To me, validation is proper presentation in Thorium, Calibre or Kindle Previewer, with no submission errors, and all else is... fussing.

But then, both of the e-book communities I noted love to fuss. And fiddle. And fix. And fine-tune. Some of us just want to publish fine digital editions without calipering the paper and spot-checking the ink density. 🙂

[Cyrusmage]

Ah, I see. I had a feeling that was the climate surrounding ebooks based on some of the forums I've been reading.

Ok, I'll have a look at the book.

I've been using Calibre to check each ebook's layout is working the way I intended, and to make sure the files work. Which is partly why I thought those errors were strange. They had no effect on how Calibre handled the file at all. It all looked normal there. But when I sent a version of the epub with errors (before I knew there were errors) to an award submission, the judges said they were having problems viewing the file.

Hopefully, that won't happen now.

I've made a few files with 3.0 now and they each seem to be working as far as I can tell. 

[James Gifford—NitroPress]

You're doing most things correctly/best practice, in general, other than having gone with EPUB 2 so long.

I hate to just rant about the whole situation, but I've spent way too much time at the disconnected ends of the field and greatly wish there was a solid "middle" of users who are neither obsessed with minutiae of code nor wedded to basement-workshop methods, tools and concepts more than a decade out of date. It's way past time for digital publishing to grow into a mature practice, as routine as producing any quality print materials using tools like InDesign, without being dragged down by allegience to either of those factions.

But if there's a pool of such "journeyman" e-publishers around, they're lost in the absoute (and largely opposite) certainties of the two extremes. So I do my best, here in this somewhat off-mainstream venue. 🙂

(There was a chance of a certain commercial branch of the field becoming a solid standard in this way, but it... was left to the fanatic disciples with predictable results..See: Santayana and Watts.)

[Derek Cross]

It's good to see Laura Brady contributing to the forum, she's a world-class ePub expert.