View Full Version : epub validation error -- image not reachable

03-07-2012, 01:32 AM
I have created a book using InDesign that is using a jpg image for its cover, which I can pick in InDesign before creating the epub. When I load the epub in Sigil and validate it I get this error:

OEBPS/Images/cover.jpg not available This resource is present in the OPF <manifest>, but it's not reachable (it's unused).

This book will be for Amazon, so I convert it to mobi with Calibre and open it with the Kindle Previewer. The cover seems fine to me. I also have placed this same jpg on the first page of the book, perhaps that's an issue. The cover.jpg is indeed within the epub file.

In any case, I don't know whether I have a problem on my hands or whether I should just ignore this and submit the book to the Amazon store.

Thanks for all comments


03-07-2012, 03:08 AM
Maybe Indesign does not care about mixed cases, but sigil does, and the resulting mobi does not. Cover.jpg versus cover.jpg

03-07-2012, 03:14 AM
Thanks for your response. Sigil points to the cover image within the content.opf file as:

<meta content="cover.jpg" name="cover" />


<item href="Images/cover.jpg" id="cover.jpg" media-type="image/jpeg" />

Within the Images folder it also shows up as cover.jpg

Where else would the mixed cases be showing up? However, if the mobi file is in no way compromized by this, then for the moment this isn't a dealbreaker. But I would like to know how to avoid it in the future.


03-07-2012, 04:43 AM
Perhaps a silly question, but where do you use your cover? There must be a xhtml file actually displaying the cover. Based on the error message, there is either no coverpage or there is a type in the coverpage.
Look for it, it is usually the first xhtml file you see in Sigil.

Without it the cover will not show.

03-07-2012, 04:51 AM
The first file in the document does contain the cover image but I placed that manually on the first page of the InDesign document. When exporting from InDesign you have the option to indicate what image should be used as the actual cover, and I chose the same jpg image. My understanding was that it was good practice to not only have a cover image but have that image within the document itself on the first page. When I view the converted mobi file in Kindle Preview, it indicates that the book does have a cover. Perhaps I'm mixing these two covers up in some way? Do you mean a typo? There doesn't seem to be a separate page just displaying the cover image.


03-07-2012, 05:00 AM
But do you have an xhtml file in Sigil referring to the cover file? The error message thrown indicates you have not.
But maybe theres an error in Sigil. I had this behaviour with Fonts, which were added in Sigil, referenced in the CSS and displayed in the preview and on my e-Reader. But sigil said,m that the fonts were not used at all.
But never had this with images.

03-07-2012, 05:40 AM
huebi, no, there is no separate file in the epub for the cover image. InDesign 5.5 is supposed to create this, but perhaps it's not doing so. It would seem the thing to do is create a separate file, then, and make all the necessary changes to the epub code. I had hoped to avoid that. Interesting point about the fonts.

03-07-2012, 05:59 AM
huebi, no, there is no separate file in the epub for the cover image.

So it is not used and thats what Sigil is telling you :)

03-07-2012, 08:18 AM
If all you're using the ePub for is as a source to create a mobi file for Amazon you can ignore that error message (as long as the cover image is designated as the cover). there is no need to create a separate cover xhtml file as the conversion process will remove any xhtml file designated as a cover anyway (mobi doesn't use it).

03-07-2012, 09:01 AM
Encouraging news, thanks, since for the moment this will be for the Kindle store. Since I hope to later submit it to other stores in ePub format, sounds like I'll have to resolve this then.

I have these two lines in the content.opf, so I guess I have this covered for the mobi version:

<item href="Images/cover.jpg" id="cover.jpg" media-type="image/jpeg" />
<item href="Images/cover_fmt.jpeg" id="cover_fmt.jpeg" media-type="image/jpeg" />

Thanks to all who have responded in this thread, and beyond that, to the many helpful members who have replied elsewhere to my queries. What a great forum!


03-07-2012, 09:32 AM
Guess you've got this fixed for your purpose, but cover_fmt.jpeg will be a file created by InDesign based on (presumably) the cover.jpg that you were linking to in the document.
So it looks like you have two files there and only one is being referenced in the epub.
Have you checked the cover html file to see what it's linking to?

03-07-2012, 10:58 AM
The thing is, there is no cover.html file in the epub, despite my specifying a cover image in InDesign.

03-07-2012, 07:28 PM
InDesign doesn't make a cover html file for you. You have to make that yourself if you want one. But if you are just doing mobi, you shouldn't include one anyway and KindleGen removes it (I think that's new, isn't it?).

Designating the cover image in InDesign is done for other reasons like telling the iTunes store what to use. It puts a meta name="cover" tag in the metadata section of your .opf file, adds the image file to the manifest and packages the image up with the epub.

Speaking of KindleGen, it is built into Kindle Previewer so you can just drag and drop you epub file onto the previewer and it will convert it to mobi. No need to use Calibre.

03-07-2012, 07:45 PM
Actually, it is important to point out the KindleGen probably only knows to strip out the cover html file if you designate a cover in the guide section of the opf file. I make that section myself because InDesign doesn't do it for you. Maybe they will on the next release.

03-08-2012, 10:34 AM
The thing is, there is no cover.html file in the epub, despite my specifying a cover image in InDesign.

That's because there is no proper "cover" definition in the ePub format, nothing wrong with your file, it's just not in the specification. The use of a <meta name="cover"> tag is an ad-hoc solution that makes sense and may work with some reading software, but there's nothing in the ePub spec that says it must work, it's only a custom metadata field that can be added (and there's no way Sigil can know the image is referenced there, because <meta> tags can contain any text, not necessarily a file id, it's the reading software who will interpret it one way or another).

You could add an XHTML file that uses the cover image, or just ignore the validator warning, it doesn't make the ePub file invalid (it would be invalid if the image did not appear in the manifest, though).