Calibre > 2.68, Kobo Touch, Added books disapear on restart

[cesarcf1977]

Hi folks,

I've been using Calibre for a while, always smoothly. Months ago, I updated to a new version and suddenly, some 25% of my ebooks in the Calibre Library appear as if they didn't exist in my device. I add them again, everything looks fine; then I eject the device, re-connect it again (it doesn't matter if after 5 minutes or 5 days), and the same issue happens. The books still exist in my device, and I can read them without problems; only the "On Device" flag in Calibre is not working for them (because the books don't show up in the device, either main memory or memory card, in Calibre).

Latest version that works for me is 2.68; anything more recent triggers the issue. I've tried both in WIN10 and Ubuntu 16.04. I haven't been able to find any pattern on the disappearing books, nothing in common across all them. It doesn't happen only to newer books added after the version update, it happens also to books I had in my library/device long before.

I also realized that the "metadata.calibre" file is updated properly when adding the books and the changes persist after ejecting the device and closing Calibre; it is upon starting Calibre that the changes to the file are undone.

I've read several posts on disappearing books, or not being able to load new one, but none exactly flags the same issues I'm experiencing. If that's the case, please, just steer me to those posts.

Thanks and regards.