I recently upgradeupgraded my server from Ubuntu V14.04 to V16.04 and now systemctl doesn't seem to work anymore.
Update Per @JdeBP deleting the screen-cleanup script resolved the problem
$ sudo rm /etc/init.d/screen-cleanup $ sudo systemctl disable transmission-daemon.service Synchronizing state of transmission-daemon.service with SysV init with /lib/systemd/systemd-sysv-install... Executing /lib/systemd/systemd-sysv-install disable transmission-daemon insserv: warning: current start runlevel(s) (empty) of script `transmission-daemon' overrides LSB defaults (2 3 4 5). insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `transmission-daemon' overrides LSB defaults (0 1 6). insserv: warning: current start runlevel(s) (empty) of script `transmission-daemon' overrides LSB defaults (2 3 4 5). insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `transmission-daemon' overrides LSB defaults (0 1 6). I can see the service is now disabled as required
systemctl status transmission-daemon ● transmission-daemon.service - Transmission BitTorrent Daemon Loaded: loaded (/lib/systemd/system/transmission-daemon.service; disabled; ve Drop-In: /etc/systemd/system/transmission-daemon.service.d └─local.conf Active: active (running) since Thu 2018-03-08 08:16:00 EST; 2 days ago Main PID: 2423 (transmission-da) Status: "Uploading 329.89 KBps, Downloading 11.04 KBps." CGroup: /system.slice/transmission-daemon.service └─2423 /usr/bin/transmission-daemon -f --log-error -g /etc/transmissi