Glo HD kobo turns off after turning the cover (in kepub)

[Bartz95]

Hello,
Yesterday I tried to convert my books from epub to kepub using Calibre.
At first everything went according to plan, the books finally no longer had various space problems, the images were displayed as they should, etc ...
But then ... it all fell apart when I ran into a pretty serious bug.
Basically some books make the kobo shut down all of a sudden.
It happens in a very specific moment and that is when I turn the cover to see the first page of the book or at the exact moment I see the cover, and these two "versions" of the bug happen with specific books.
The weird thing is that (when it doesn't crash right away) I can go through the book by selecting the first page from the index and everything works as it should.

I add that I also tried kepubify, encountering the same problem and that my Kobo Glo HD is updated to the latest firmware version.

Thanks in advance to all those who can help me (and sorry for my English)

[Poppaea]

Originally Posted by Bartz95

Hello,
Yesterday I tried to convert my books from epub to kepub using Calibre.
At first everything went according to plan, the books finally no longer had various space problems, the images were displayed as they should, etc ...
But then ... it all fell apart when I ran into a pretty serious bug.
Basically some books make the kobo shut down all of a sudden.
It happens in a very specific moment and that is when I turn the cover to see the first page of the book or at the exact moment I see the cover, and these two "versions" of the bug happen with specific books.
The weird thing is that (when it doesn't crash right away) I can go through the book by selecting the first page from the index and everything works as it should.

I add that I also tried kepubify, encountering the same problem and that my Kobo Glo HD is updated to the latest firmware version.

Thanks in advance to all those who can help me (and sorry for my English)

I can't tell you what causes this, but the latest firmware version (4.31.xxx) is very buggy.

Take a look at the thread about it, to find out if your specific problem is encountered by anyone else. In the thread, you'll find how to roll back to the version before (4.30.xxxx), too. It is very easy to roll back. Only thing to be mindful of is to keep the wifi turned off or the reader starts synching back to the latest version.

I had a lot of problems while on 4.31. and the rollback solved all of them for me.

[Bartz95]

Originally Posted by Poppaea

I can't tell you what causes this, but the latest firmware version (4.31.xxx) is very buggy.

Take a look at the thread about it, to find out if your specific problem is encountered by anyone else. In the thread, you'll find how to roll back to the version before (4.30.xxxx), too. It is very easy to roll back. Only thing to be mindful of is to keep the wifi turned off or the reader starts synching back to the latest version.

I had a lot of problems while on 4.31. and the rollback solved all of them for me.

Thanks for the advice, I'll try to do as you said and see how it goes.

However I discovered another strange thing, if I remove one of the problematic books from the kobo and then put it back everything is fine until ... I mark it as completed, then it starts crashing again.
This leads me to think that the book is not the problem but rather something related to the kobo operating system... perhaps a poorly developed update?

[ZodWallop]

I am no help on your actual issue. I'm just replying to:

Originally Posted by Bartz95

Yesterday I tried to convert my books from epub to kepub using Calibre.

If you install KoboTouchExtended plugin, you can keep epubs on your hard drive and Calibre will send books to the Kobo as kepubs. No need to convert them yourself.

[rtiangha]

I've noticed something similar too when reading a kepub and it tries to load certain (full size?) images, also on a Glo HD.

If I'm lucky, it's in the middle of the book and I can skip ahead using the table of contents and go backwards, or the slider to go past the problematic page (the image usually renders fine in the preview window, but when I tap it to go to the page, it crashes when it tries to load the image proper.).

If I'm not lucky, it's the cover and it'll immediately crash when I try to open the book. What I have to do in that case is replace the cover image, either by opening it in GIMP, making any kind of change (ex. convert it to black and white, scale it down, crop it, etc.) and replacing it with that, or using Calibre to source a new cover from somewhere else.

When I say crash, I mean it automatically turns off. I'm not sure what it is about these images that triggers a crash, and it isn't a 4.31 issue; I think it started back in the 4.20s; maybe 4.25 or 4.26 or so (but don't quote me on that; haven't kept track too closely). All I remember is that one book I had no problems opening before started to give me issues after a firmware update; I replaced the cover and re-uploaded it and it was fine. I can't remember what book it was and I've just learned to deal with it. Haven't tried other things like using an epub version instead or looking into the book code or image settings; no time. They were sideloaded though, converted with kepubify.

[Bartz95]

Originally Posted by ZodWallop

I am no help on your actual issue. I'm just replying to:

If you install KoboTouchExtended plugin, you can keep epubs on your hard drive and Calibre will send books to the Kobo as kepubs. No need to convert them yourself.

Yes, that's exactly the method I'm using to convert epubs.
I select the book or books that interest me, right click, send to device, send specific format to, device memory, double click kepub.

Originally Posted by rtiangha

I've noticed something similar too when reading a kepub and it tries to load certain (full size?) images, also on a Glo HD.

If I'm lucky, it's in the middle of the book and I can skip ahead using the table of contents and go backwards, or the slider to go past the problematic page (the image usually renders fine in the preview window, but when I tap it to go to the page, it crashes when it tries to load the image proper.).

If I'm not lucky, it's the cover and it'll immediately crash when I try to open the book. What I have to do in that case is replace the cover image, either by opening it in GIMP, making any kind of change (ex. convert it to black and white, scale it down, crop it, etc.) and replacing it with that, or using Calibre to source a new cover from somewhere else.

When I say crash, I mean it automatically turns off. I'm not sure what it is about these images that triggers a crash, and it isn't a 4.31 issue; I think it started back in the 4.20s; maybe 4.25 or 4.26 or so (but don't quote me on that; haven't kept track too closely). All I remember is that one book I had no problems opening before started to give me issues after a firmware update; I replaced the cover and re-uploaded it and it was fine. I can't remember what book it was and I've just learned to deal with it. Haven't tried other things like using an epub version instead or looking into the book code or image settings; no time. They were sideloaded though, converted with kepubify.

A solution to your problem could be to change the page setup in common options on Calibre from something like "tablet" which does not alter image resolution to "generic e-ink" this way the images should be lighter (but sadly also a a little more blurry) and then, to make your books "receive" the change of setting, select your books, then convert books and on the first page select restore defaults or ... remove all your books from caliber and then add them again, this should work.
Obviously, do some backups, and if you don't want to waste any time, you might want to try on a single book to see if the method works.

However what happens to you seems different, because I have books with very heavy images, which do not have this problem.

[rtiangha]

Originally Posted by Bartz95

However what happens to you seems different, because I have books with very heavy images, which do not have this problem.

So do I. Japanese light novels, comics, photo books, etc. I'd say 99% of my books work properly, it's just that whenever I've encountered the weird auto turn off problem, it has only ever happened when trying to load certain full page images.

Curious: When you turn the cover and your device turns off, is the next page also an image? Some books are like that with a cover followed by an image file of a title page.

[davidfor]

Originally Posted by rtiangha

So do I. Japanese light novels, comics, photo books, etc. I'd say 99% of my books work properly, it's just that whenever I've encountered the weird auto turn off problem, it has only ever happened when trying to load certain full page images.

Curious: When you turn the cover and your device turns off, is the next page also an image? Some books are like that with a cover followed by an image file of a title page.

Are you replacing the book using calibre? And if so, is there a chance that the structure of the book has changed? That means has the something changed in the internal files or the ToC. I have a vague feeling that I have seen this with books that have been replaced via calibre. But, it was a long time ago.

Otherwise, it is probably something unusual about the book. Either the image or the for it or the next page has something unexpected in it. Or, if it is only happening with 4.31, then it could be font related. I think we would need to see an example to be able to guess.

[rtiangha]

Originally Posted by davidfor

Are you replacing the book using calibre? And if so, is there a chance that the structure of the book has changed? That means has the something changed in the internal files or the ToC. I have a vague feeling that I have seen this with books that have been replaced via calibre. But, it was a long time ago.

No, nothing like that (I think). Basically, I use Calibre to set metadata and maybe replace the cover with a higher resolution version if available, use the polish feature to replace cover and metadata, save epub to disk, run kepubify on it then transfer the book by wifi because my usb port is flakey and will no longer hold a stable connection; I can barely charge it as long as I hold the cable a certain way. And while it can happen on a cover, it has also happened on images in the middle of a book (the cover is more noticeable because it fails fast). The only pattern I've seen in all my cases is that the crash happens on full sized images; I've never noticed it on a page with small images and text.

Otherwise, it is probably something unusual about the book. Either the image or the for it or the next page has something unexpected in it. Or, if it is only happening with 4.31, then it could be font related. I think we would need to see an example to be able to guess.

No, for me, this started some time in the 4.20s, first with books already on the device loaded back when I was running an older version (ex. 4.15) that I had finished and wanted to reread or to check a reference, and every so often with a new book I'll load. But still very rare. I've been deleting the problematic book files as I encounter them and fix them by replacing the images, but if I encounter the problem again, I'll make sure to save the file.

[Bartz95]

Originally Posted by rtiangha

So do I. Japanese light novels, comics, photo books, etc. I'd say 99% of my books work properly, it's just that whenever I've encountered the weird auto turn off problem, it has only ever happened when trying to load certain full page images.

Curious: When you turn the cover and your device turns off, is the next page also an image? Some books are like that with a cover followed by an image file of a title page.

No, usually what causes the kobo to crash is the turn between the cover and the index.
A curious thing, right now I have one of these books under my eyes.
I opened the book and it started from the cover, I went ahead and it crashed, then I tried to turn the kobo back on, I reopened the book and I went on with the chapter selection, then I went back to the cover by turning the pages, in this way, passing from the cover to the book itself, the kobo does not crash.

Another oddity, one of these problematic books crashes as soon as it loads the cover, but the particular thing is that it does so only after it has been on the kobo for some time, it works perfectly after being imported.