Connection attempt failed with "ECONNREFUSED - Connection refused by server

[efe55]

firewall enabled? Did you check

systemctl status firewalld

also check if proftpd is running

systemctl status proftpd

Don't double post.

login as: root
root@192.168.100.12's password:
Last login: Wed Dec 12 13:54:45 2018 from 192.168.100.2
[root@server ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)
[root@server ~]# systemctl status proftpd
Unit proftpd.service could not be found.
[root@server ~]#

What's the solution???