csf error path to iptables is either not set or incorrect

Whem install csf firewall on Ubuntu 20.04, i get following error

root@ok:~# csf
*Error* The path to iptables is either not set or incorrect for IPTABLES [/usr/sbin/ip6tables] in /etc/csf/csf.conf at /usr/local/csf/lib/ConfigServer/URLGet.pm line 26.
Compilation failed in require at /usr/sbin/csf line 21.
BEGIN failed--compilation aborted at /usr/sbin/csf line 21.
root@ok:~#

This is because path for iptables is changed in Ubuntu 20.04. To fix the error edit csf.conf

vi /etc/csf/csf.conf

Find

IPTABLES = "/sbin/iptables"
IPTABLES_SAVE = "/sbin/iptables-save"
IPTABLES_RESTORE = "/sbin/iptables-restore"
IP6TABLES = "/sbin/ip6tables"
IP6TABLES_SAVE = "/sbin/ip6tables-save"
IP6TABLES_RESTORE = "/sbin/ip6tables-restore"

Replace with

IPTABLES = "/usr/sbin/iptables"
IPTABLES_SAVE = "/usr/sbin/iptables-save"
IPTABLES_RESTORE = "/usr/sbin/iptables-restore"
IP6TABLES = "/usr/sbin/ip6tables"
IP6TABLES_SAVE = "/usr/sbin/ip6tables-save"
IP6TABLES_RESTORE = "/usr/sbin/ip6tables-restore"

Now restart csf with csf -r, it will work.

csf -r
systemctl restart lfd

See csf