how to unmask service munin

[robert rottermann]

Hi there

I try to install munin on ubunu18.04

now when I try to start the munin service I get a message that it is masked.

     root at elfero-test:/etc/munin/plugins# service munin start
     Failed to start munin.service: Unit munin.service is masked.

I try to unmask it:

     systemctl unmask munin.service

no output.

I try to enable it:

     systemctl enable munin.service
     Synchronizing state of munin.service with SysV service script with 
/lib/systemd/systemd-sysv-install.
     Executing: /lib/systemd/systemd-sysv-install enable munin
     Failed to enable unit: Unit file /lib/systemd/system/munin.service 
is masked.


How can I proceed to enable the service?

thanks for your input

robert