Kobo freezing after transferring ePub

[onaeD]

After transferring an ePub file (from Manning Publications) and "ejecting" my Kobo, it freezes during the "processing new content" step, requiring a hard reset, after which the book doesn't appear in the library (although still being on the File System)

The progress-bar just sits at about 10%

The file is about 13MB.

Anyone else having a similair issue?

[pholy]

I have had a similar problem with a couple of books. I found that when I unzipped them, they had a huge .css file. When I opened that I found thousands of classes defined, mostly identical. It was a pretty bad conversion, and not much I could do. (except try a different brand of reader...) A 13MB epub is pretty huge, it may have a lot of pictures or embedded fonts. (It should not be a malformed epub file, but it is possible.) I'm not sure exactly what makes it choke.

The files I looked at did not have DRM, of course, or I couldn't have looked at them. I think they were from BooksOnBoard, but I'm not sure.

[artificial]

Originally Posted by pholy

It should not be a malformed epub file, but it is possible.

Most converted epubs are a mess, and don't conform to the epub specification.

I've had an epub that my Kobo Reader refused to read (didn't crash, but wouldn't display the book), though my desktop epub viewer handled it without concern.

I ran the file through an epub validator, and fixed all of the errors by hand, after which the Kobo Reader would display the book correctly.

Admittedly, there was a major problem with this particular epub: all the html files contained a hash (#) in the filename, and given that the hash has a special meaning within URLs I'm not surprised the Kobo Reader choked when parsing the epub!

But my story does point to the unreliability of the conversion process, and the fact that certain epubs can mess with your ereader.

[onaeD]

Thanks. I would have expected an ePub eBook purchased directly from the publisher would have conformed to the standard

Thanks for the link to the validator. I'll run my eBook through it and contact Manning Publications with any results.



Oh yes, I forgot to mention my Desktop ePub reader (Mobipocket Reader) displays the book no problem.

[artificial]

Originally Posted by onaeD

Thanks. I would have expected an ePub eBook purchased directly from the publisher would have conformed to the standard

Sorry, I overlooked the fact that it was a purchased epub when I read your original post! My experience only relates to epubs converted from another format using Calibre.

[PeterT]

Originally Posted by onaeD

Oh yes, I forgot to mention my Desktop ePub reader (Mobipocket Reader) displays the book no problem.

I didn't know Mobipocket Reader could read ePubs! My version 6.02 doesn't seem able to.

[RedRoverJ]

Mobipocket will convert to mobi format when you import an ePub.

[onaeD]

Originally Posted by onaeD

I'll run my eBook through it and contact Manning Publications with any results.

Sure enough, the ePub validator indicated a host of problems. I've contacted Manning Publishing to let them know

[techie42]

Originally Posted by artificial

Most converted epubs are a mess, and don't conform to the epub specification.
...

But my story does point to the unreliability of the conversion process, and the fact that certain epubs can mess with your ereader.

I wqas using Calibre to convert files and (after I got the hang of it) I have had very few problems (aisde from the firmware bug in kobo text resize.)

[artificial]

Originally Posted by techie42

I wqas using Calibre to convert files and (after I got the hang of it) I have had very few problems

I hope I didn't sound like I was running down Calibre! I think Calibre is the bees knees!

It's just my experience that converted epubs don't conform to the epub specification, although most non-validating epubs will render perfectly well nonetheless.

I would compare it to web page validation - the vast majority of web pages don't conform the W3C specifications, but web browsers manage to render them without observable problems.

[Verencat]

Originally Posted by artificial

Most converted epubs are a mess, and don't conform to the epub specification.

I've had an epub that my Kobo Reader refused to read (didn't crash, but wouldn't display the book), though my desktop epub viewer handled it without concern.

I ran the file through an epub validator, and fixed all of the errors by hand, after which the Kobo Reader would display the book correctly.

Admittedly, there was a major problem with this particular epub: all the html files contained a hash (#) in the filename, and given that the hash has a special meaning within URLs I'm not surprised the Kobo Reader choked when parsing the epub!

But my story does point to the unreliability of the conversion process, and the fact that certain epubs can mess with your ereader.

So I'm screwed.

Did I type that out loud?

I crashed the Kobo twice with epubs that I converted myself with Calibre, and after running the books through the validator (thanks for that), I've found loads of errors. But of course I have no clue of what they mean, nor how to fix them. I'll try converting the books to pdf, I can handle them a little better.

Thanks for this thread, everyone, I can now stop banging my head on the wall!

edit: marvelous pdf. Yay. Off to read now.

[saskee]

I had a similar problem after attempting to transfer a book using calibre. The book was an epub format. I checked it with epub validator and it came back as valid. After resetting (several times) and attempting to remove the offending file using calibre, the same problem with freezing kept occuring. Even if I just plugged in the Kobo and then ejected and unplugged, the same freezing would occur.

I then reset the machine using the Kobo menu which was supposed to remove all books and settings that I had added. It seemed to do that. I then tried to use the Kobo software to add back a book purchased from Kobobooks and the same freeze occured. However the Kobo showed the book I added except for the cover.

Calibre still shows the books that I had added since getting the Kobo as present on the device.

I'm stumped, but before I give up and return the device or seek technical support I thought I'd ask if anyone else has had this problem and solved it.

Thank you,

Jim

[Stinger]

I then tried to use the Kobo software to add back a book purchased from Kobobooks and the same freeze occured(sic). However the Kobo showed the book I added except for the cover.

Hmmm, this is the first time I've heard of someone having major problems with an official 'KoboBooks' book, especially loaded in through the software. For reference sake, which book was it? Maybe someone else had made the same purchase from Kobo and can provide specific insights.

Calibre still shows the books that I had added since getting the Kobo as present on the device.

This is just plain weird... Calibre doesn't have a cache of what books are on the device. It just scans for epub files and reads the metadata (can be disabled) to get the device book list. Can you take a look at the Kobo drive through a file manager and see if the books are still there? (I believe last time I did a factory reset, it didn't actually remove plain epub files I dragged on myself)


Just out of curiosity, when you say "freeze", how long did you wait before resetting? I've loaded on a few books with heavy CSS styles that took over 2-3 minutes to process.

[saskee]

Ok...the Kobobook was "Great Reset" which had worked fine before the last couple of days, it was in attempting to reload after my own great reset that it wouldn't completely process. Interestingly enough the book shows on the Kobo (without cover), but when I examined the device directory directly I can't see it. Some other books and newspapers that I had added, however do show up on the device drive although they do not show up when trying to access them on the Kobo itself. The device drive also shows a couple of empty folders of books that I had removed. I can view the books that the device can't see using the Adobe software.

Calibre shows some, but not all, books that were there before I used the device reset, but doesn't show the Great Reset which the Kobo does.

As for the time I have left the Kobo "processing" for over 30 minutes and the indicator doohickey didn't move past about 10% completion.

Thanks for your help,
Jim

[Stinger]

Interestingly enough the book shows on the Kobo (without cover), but when I examined the device directory directly I can't see it.

This is normal. Books you buy from KoboBooks and load onto the device through the official desktop software are injected directly into the SQlite database. (\.kobo\KoboReader.sqlite)

Some other books and newspapers that I had added, however do show up on the device drive although they do not show up when trying to access them on the Kobo itself.

I would guess that one of these files is the source of your problems. Delete them. Then re-add them, 1 by 1 until you discover which one is causing problems. There have been a few people that have reported the same freezing/missing books issues you have, and have narrowed it down to corrupt/funky specific books.

Calibre shows some, but not all, books that were there before I used the device reset, but doesn't show the Great Reset which the Kobo does.

This is also completely normal. Calibre does not read the contents of the Kobo SQlite database, which, like I mentioned above, is where books loaded through the desktop app are stored.
One of our members here is working on a device driver for Calibre that can handle the SQlite database, and even selectively remove any of the 100 free included books:
https://www.mobileread.com/forums/showthread.php?t=85226

Be warned, it's still in beta testing, so I would make a copy of the SQlite database file (i indicated the path above) before using this driver.