Fwd: Update Kolab16 on Debian 10 broken? still broken?

Hey,

I have a few Kolab 16 Installations running on Debian 10.
Installed in summer 2021...

Ive been trying to update (apt-get upgrade) them for a while now. But
for at least half a year now, I cant install updates.

First run seems to work, but there are withheld packages, and webmail
cant find mailboxes anmyore. Ive tried keeping or replacing the
/etc/roundcubemail/defaults.inc.php file, seems not to matter

see log first run: https://controlc.com/19c56c2e

post run webmail does not work anymore. I did not check much further...
and if it would work, it still leaves a broken system wanting to
install/remove packages...

see https://controlc.com/de924f01

next run with dist-upgrade, or presumibly, trying to install roundcube
directly...
and then it all breaks and flies appart.

https://controlc.com/14319646


I really hope there is a move forward. any help would be appreciated.

thanks in advance
Matthias