package:fail2ban:0.9.7-2
Installing new version of config file /etc/fail2ban/jail.conf ...
Job for fail2ban.service failed because the control process exited with error code.
See "systemctl  status fail2ban.service" and "journalctl  -xe" for details.
invoke-rc.d: initscript fail2ban, action "start" failed.
● fail2ban.service - Fail2Ban Service
   Loaded: loaded (/lib/systemd/system/fail2ban.service; enabled; vendor preset: enabled)
   Active: activating (auto-restart) (Result: exit-code) since Mon 2017-10-30 16:51:45 EDT; 5ms ago
     Docs: man:fail2ban(1)
  Process: 26620 ExecStart=/usr/bin/fail2ban-client -x start (code=exited, status=255)

Oct 30 16:51:45 ashutosh-OptiPlex-7010 systemd[1]: fail2ban.service: Unit entered failed state.
Oct 30 16:51:45 ashutosh-OptiPlex-7010 systemd[1]: fail2ban.service: Failed with result 'exit-code'.
dpkg: error processing package fail2ban (--configure):
 subprocess installed post-installation script returned error exit status 1