[MauriceH]

OK, that explanation makes sense, and explains a lot of things.

Thanks!

I guess I somewhat got lucky in that it ended up getting fixed, and not completely blown up.

My saga is, however, not quite over.
Today I downloaded a new EPUB, and started Calibre on my PC.

I went to add the book to my collection, and saw a long string of errors.
Unfortunately I did not capture that.
Afterwards, however, I see that the new book has been added, is in the master list, and is readable, at least on my PC.

Is there anything you could suggest I should now check?

Regards,
Maurice