Looking at the logs, the error is:
useradd: cannot lock /etc/group; try again later.
adduser: `/usr/sbin/useradd -d /var/run/sshd -g nogroup -s /usr/sbin/nologin -u 115 sshd' returned error code 10. Exiting.
I suspect there is a stale /etc/group.lock file that you should remove (sudo rm /etc/group.lock). Please confirm that it allows to solve the situation. Then this bug would be a duplicate of bug 523896.
Looking at the logs, the error is:
useradd: cannot lock /etc/group; try again later.
adduser: `/usr/sbin/useradd -d /var/run/sshd -g nogroup -s /usr/sbin/nologin -u 115 sshd' returned error code 10. Exiting.
I suspect there is a stale /etc/group.lock file that you should remove (sudo rm /etc/group.lock). Please confirm that it allows to solve the situation. Then this bug would be a duplicate of bug 523896.