Thanks for filing this bug in Ubuntu.
There are some interesting warnings in the logs you provided:
WARN: uid is 0 but '/' is owned by 1004 WARN: / is group writable!
and
Setting up openssh-server (1:7.2p2-4ubuntu2.6) ... Unsafe symlinks encountered in /var/run/sshd, refusing.
More details should be present in /var/log/syslog, /var/log/auth.log and/or in the output of journalctl -xe.
Could you please inspect those and report back, or attach them to this bug?
Thanks for filing this bug in Ubuntu.
There are some interesting warnings in the logs you provided:
WARN: uid is 0 but '/' is owned by 1004
WARN: / is group writable!
and
Setting up openssh-server (1:7.2p2- 4ubuntu2. 6) ...
Unsafe symlinks encountered in /var/run/sshd, refusing.
More details should be present in /var/log/syslog, /var/log/auth.log and/or in the output of journalctl -xe.
Could you please inspect those and report back, or attach them to this bug?