[eBookWorm21]

I think I may have shot myself in the foot, so to speak, by removing the EPUBs from my Calibre Library to Apple Books, and then deleting them from my Calibre Library. I realized afterwards, with 20/20 hindsight, that there were other files in the ebook's Calibre Library folder that it created when I originally added them the the Library.

Calibre has some features that Apple Books doesn't have, so I'd like to copy my ebooks back to Calibre. I have a full copy of my library on an external hard drive. I'm running macOS Ventura 13 and Calibre 6.8.0, which seems to be the most current version.

I am getting errors like this when I add some of the EPUBs back to Calibre:

calibre, version 6.8.0
WARNING: Errors while adding: There were problems adding some files, click "Show details" for more information
----------------------------------------------------------------------
Failed to add the file /Volumes/WD 2TB External Drive/Apple Books PDFs backup/'Salem's Lot.epub to the book: /Volumes/WD 2TB External Drive/Apple Books PDFs backup/'Salem's Lot
With error:
Traceback (most recent call last):
File "calibre/gui2/add.py", line 487, in add_formats
File "calibre/db/cache.py", line 1810, in add_format
IsADirectoryError: [Errno 21] Is a directory: "/Volumes/WD 2TB External Drive/Apple Books PDFs backup/'Salem's Lot.epub"

When I click through the error, it add it to the Library, but in the TITLE column, it shows the file path where the file resides, instead of the real title. No Author information is shown.

When I double-click to open it from the Library, I get this error:

calibre, version 6.8.0
ERROR: Cannot view: /Volumes/WD 2TB External Drive/Apple Books PDFs backup/'Salem's Lot has no available formats.


Is there a way to add these ebooks back to Calibre Library?

(If there's any helpful detail I omitted, please advise)

Thank you