[aceflor]

I don't know why, but it failed, each time I tried (3 Times in total). I zipped the directories per date, as to be sure to cover every new book since the end of August. My Library shows Directories per Author, and sub-directories per book, and as I suspected some books might be corrupted I had to re-add them methodically to find the bad ones.

3 books turned out to be indeed corrupted.

I recovered all books but those 3, all tags, but some series are missing. Oddly, too, azw3 formats (converted through Calibre) have sometimes disappeared.

I can only remember a transfer between my laptop and my kindle fire done through CC going wrong (as in giving me the corrupt database message), ejecting the fire, exiting Calibre and not being able to start it again correctly.

Now that my library is rescued, I will need to empty the fire and refill it again. Probably not going to use CC this time around, and will not fill the fire before having done a backup of the library anyway.