ProFTPD Server wont start?

Failed to start FTP server :

Job for proftpd.service failed because the control process exited with error code. See “systemctl status proftpd.service” and “journalctl -xe” for details.

The journalctl -xe shows some usefull info:

proftpd: fatal: SFTPHostKey: Unable to use ‘/etc/ssh/ssh_host_rsa_key’ as host key, as it is group- or world-accessible on line 436 of ‘/etc/proftpd.conf’

Solution:

Locate the .conf file:

/etc/proftpd.conf

At the end of the .conf file comment the lines…

# SFTPHostKey /etc/ssh/ssh_host_rsa_key
# SFTPHostKey /etc/ssh/ssh_host_dsa_key

Start ProFTPD Server

et voilà!