Clara HD EPUB completely blank (aside from cover)

[sdj]

Hi there,

This is my first post here, so I apologize in advance if I do anything wrong.

I have (very) recently purchased a Kobo Clara HD, mainly because I wanted to be able to side-load EPUBs onto it. I've read 2 books without problems so far, but I'm now facing an annoying issue with the third book.

When I open it, I can see the cover picture normally, but everything else is blank. The interesting part is that I can still access the table of contents and navigate through the chapters, but they're all blank.

I did some research and found this thread:

https://www.mobileread.com/forums/sh...d.php?t=270096

which kind of reports the same problem I'm seeing. I did what was suggested (i.e., edited the book with Calibre, checked for errors, corrected as many of them as I could), but the problem still persists. Currently, I'm seeing 3 warnings on Calibre's editor:

WARNING: The CSS font-family name Minion Pro does not match the actual font name Minion****[page_styles1.css]
WARNING: The CSS font-family name Minion Pro does not match the actual font name Minion****[page_styles1.css]
WARNING: The CSS font-family name Minion Pro does not match the actual font name Minion****[page_styles1.css]

I think these should not interfere with the rendering, but I'm not absolutely sure.

Does anyone know what could be causing this, and how I can try to solve the problem? Any advice is welcome; I'm really new to the e-reader scenario.

Thanks in advance!

P.S.: I'm running the latest available stock firmware, without any third-party programs. I can post more information about the book if needed.

[rashkae]

Since you seem to be a fairly technically savvy individual, we can get right to the meat without playing guessing games.

Install the ScrambleEbook plugin in calibre, scramble your epub, and upload a copy here, (might have to use a file host, like transfer.sh, and post a link.)

[sdj]

Originally Posted by rashkae

Since you seem to be a fairly technically savvy individual, we can get right to the meat without playing guessing games.

Install the ScrambleEbook plugin in calibre, scramble your epub, and upload a copy here, (might have to use a file host, like transfer.sh, and post a link.)

Thanks for the reply.

I'm attaching the scrambled ebook here. Let me know if you need more info, and I'll be happy to provide.

Cheers.

[sdj]

Originally Posted by rashkae

Since you seem to be a fairly technically savvy individual, we can get right to the meat without playing guessing games.

Install the ScrambleEbook plugin in calibre, scramble your epub, and upload a copy here, (might have to use a file host, like transfer.sh, and post a link.)

Oh, and I forgot to say: I'd really appreciate if you could give me a walkthrough (even if it's a superficial one) on how one can debug and hopefully fix these problems.

TIA.

[rashkae]

The " color: inherit;" directives in the css stylesheet are what the Kobo is unable to render. I've seen this before, but it's such a rare thing, I had forgotten about it.

You can fix the epub by editing in Calibre, Tools Menu, Filter Style Inforation, check Colors, Ok Button, and Close Button.
Save the Epub.

Alternatively,

I am personally a big fan of using Kobo's native file format, (generally called Kepub here.) You can do that by installing the KoboTouchExtended plugin in Calibre, and use Calibre to send the book to the Kobo.

[sdj]

Originally Posted by rashkae

The " color: inherit;" directives in the css stylesheet are what the Kobo is unable to render. I've seen this before, but it's such a rare thing, I had forgotten about it.

You can fix the epub by editing in Calibre, Tools Menu, Filter Style Inforation, check Colors, Ok Button, and Close Button.
Save the Epub.

This is awesome, thank you so much for the help!

I had a guess that the problem was either with the CSS or with the fonts, but I didn't know how to pinpoint it exactly. If you hadn't found the issue, I'd probably have started to remove parts of the CSS to find the culprit...

I'm wondering, is there an easier way to diagnose these issues?

Alternatively,

I am personally a big fan of using Kobo's native file format, (generally called Kepub here.) You can do that by installing the KoboTouchExtended plugin in Calibre, and use Calibre to send the book to the Kobo.

Oh, thanks for letting me know, I had no idea about Kepub. I've just installed the plugin and am using it now.

Thanks again.

[booklover6]

Use the Edit Book function in Calibre. It will show you problematic CSS

[JSWolf]

Originally Posted by rashkae

Since you seem to be a fairly technically savvy individual, we can get right to the meat without playing guessing games.

Install the ScrambleEbook plugin in calibre, scramble your epub, and upload a copy here, (might have to use a file host, like transfer.sh, and post a link.)

And install the epubcheck editor plugin as it catches more errors.

[JSWolf]

Originally Posted by rashkae

The " color: inherit;" directives in the css stylesheet are what the Kobo is unable to render. I've seen this before, but it's such a rare thing, I had forgotten about it.

You can fix the epub by editing in Calibre, Tools Menu, Filter Style Inforation, check Colors, Ok Button, and Close Button.
Save the Epub.

Alternatively,

I am personally a big fan of using Kobo's native file format, (generally called Kepub here.) You can do that by installing the KoboTouchExtended plugin in Calibre, and use Calibre to send the book to the Kobo.

And I am not a fan of KePub because ePub does a much better job at typesetting then KePub. KePub can be not nice depending on a number of things.

[davidfor]

Originally Posted by JSWolf

And install the epubcheck editor plugin as it catches more errors.

Which wouldn't have helped in this case. And honestly, I doubt that epubcheck will find any errors that that the error checking built-in to the calibre editor didn't find, and also caused a problem on any modern ereader. If you know of one, please tell me.

Of course, the calibre editor error checking wouldn't have helped either as this is not an error in the book.

[sdj]

Originally Posted by booklover6

Use the Edit Book function in Calibre. It will show you problematic CSS

I did use the Edit Book functionality (as I said in the initial post), but unfortunately it wasn't able determine the exact reason for this problem. In fact, it didn't even mention the "color: inherit;" part.

What I was looking for was a better way to diagnose these specific problems with Kobo e-readers. It seems that the "best" solution is "trial & error", in the end...

[JSWolf]

I remove all CSS lines that use inherit as I find they actually have no use. Lines with auto also go and in most cases so do line-height. justify: left also goes. I also remove silly font sizes that are 1em or smaller. Any px or pt I convert to em. And thee % for spacing I change to a more reasonable em. The only % I leave is for hr and images.

There can be a lot of garbage in CSS of commercial eBooks. There can even be more then 100 unused CSS classes. That's why I always use the option to get rid of extra CSS. It ets rid of extra CSS in styles and HTML.

I also combine multiple CSS into one because I find multiple CSS to be a bad idea.

When I am done, I have fairly clean CSS and fairly clean HTML. So it makes finding any issues that much easier. Plus, I have the eBook formatted rather well and it's easy to then use the margins, line height and font and font size settings as desired.