Hi everybody,
I must start apologising for my english: it's only the fourth of my languages (spanish is the first, my mother's tongue). Please, be kind enough to ignore my faults...
I've a Kobo Aura HD, with a 32 Gb SD card, in wich some thousands of books. And I've seen this message several times when trying to copy in the memory card (I've tried: it also happens if I try to copy to Kobo's maim memory) new books. I don't know why. If you look to the details of the error message, I can see the title of a book, and it seems to be this book who produces the error when Calibre tries to copy to the Kobo device.
After some trials, I've found that the following procedure corrects the error:
- Convert the book from original format (im my case, always ePub) to another format (in general, I convert ot MOBI format)
- Delete the original ePub file
- Convert again the book, from MOBI to ePub
- Delete the MOBI file (you can keep all the two formats, if you want)
- Send the book to the Kobo device: no error is detected any more
For me, the real annoying thing is that, when I'm copying new books to the Kobo device (some times, several hundreds), if a book produces this error, the all task is cancelled (that is, if the book is at the last of the list, you've lost a lot of time transferring books that, finally, will not appear in the device).
I suppose this is a known problem for all Kobo's users (well, I suppose Kobo has not developped a fully different OS for every of hes devices). So, my questions to Calibre community:
- Could be it possible to open a "ticket" to Calibre's developpers, to check this problem, and try to do an utility allowing the checking of a list of files before trying to copy them in the device
- As it seems this is could be a Kobo's specific problem, could the Calibre community address this problem to Kobo company? (I have the feeling that, if I report directly this problem to Kobo, Kobo will ignore me)

Thnak you very much for any positive answer