At the minimum this affects 2 daedalus workstations. YMMV

Upgraded from thunderbird:amd64=1:115.16.0esr-1~deb12u1

to 128.4.0esr after waiting a couple days after the release to search
for dire warnings, as usual.

The usual web page was produced "welcome....",the link to the release
notes in the mail client produces a "page does not exist" error.

After upgrade clients are no longer able to log in to imap server with a
login failed/password message.

(in these cases imap.zoho.com).

Entering passwords manually fails as well, with no diagnostics other
than the failure dialog.

The logs found in thunderbird (CTRL-SHFT-J) are useless showing only

 No such JSProcessActor 'BrowserToolboxDevToolsProcess'

nothing in /var/log/* other than the usual AppArmor "ALLOWED" messages.


I had to resort to downgrading to 115.16 followed with the recommended
'thunderbird -profilemanager --allow-downgrade' which, in turn, wiped
out the local contacts and some settings.  Mail did resume functioning,
though.