This give little to no info for anyone reading what or where this is asking about??

Nach neuem Login kann ich mein Adressbuch nicht mehr finden! Was ist zu tun?

Firefox doesn't have an address book.

Is this a question about Thunderbird or about Firefox ? If the question is about Thunderbird then we can move the question thread to Thunderbird Support.

It is a question about Thunderbird.

translated: After a new login I can no longer find my address book! What should I do?

When you say 'after a new login' - do you mean you created a new profile or a new existing mail account or you updated your mail account password ?

Thunderbird starts up when you click on the shortcut icon to start Thunderbird - there is no login, so I'm trying to understand what you mean.

Did Thunderbird start up and look empty so you had to create a mail account for your email address?

When you select 'Menu icon' > 'Tools' > 'Address book' OR click on the 'Address Book shortcut icon in the 'spaces Toolbar, the 'Address Book' should open in a new tab.

What do you see? Do you see 'Personal Address Book' and 'Collected Addresses' in left pane ? Do you see those address books but they are empty ?

What OS are you using ? Linux, MAC or Windows ? What version of Thunderbird are you using?