Форум спільноти Thunderbird

I have moved my entire hard disk to a new computer and upgraded to Windows 11. My professional consult did it actually, I don' know how. But he moved the disk to the new computer and cloned its content to the new hard disk. In my address book all folders are empty, all. When creating a new mail, the addresses are all there so I can send emails to the people I want, even to groups. When creating a new sending list I can do so by typing the desired persons and their addresses will show. So all contacts are somewhere on the computer. But the folders are empty, so I can't drag and drop contacts to create a sending list. I can create new contacts and place them in any of the folders, but that will probably f-k up things. I'd be glad if it is possible to restore my address book. I realized that there are quit a lot of contacts that are obsolete, which I want to delete. I'm not native English speaking so forgive me if I got some terminology wrong.

I'm using TB 144.0.1 on a Mac desktop. When I open my address book, several come up. "Personal Address Book" is the default, which is fine by me; I can add, subtract as I wish. There are two others, "Collected Addresses" and "Mac OS X Address Book." The latter is obsolete with numerous bad addresses in it, but even though clicking the ellipses brings a speed menu containing "Delete," selecting it and confirming my desire to delete the address book has no effect. Why have a command purportedly available that doesn't work? My Mac mini uses MacOS Tahoe 26.1, and the obsolete "Mac OS X Address Book" serves only to misdirect my outgoing mail. How can I delete it?