I did try doing that.
Here is a result:
root@piplite:/# ufw disable
Firewall stopped and disabled on system startup
root@piplite:/# ufw enable
ERROR: problem running init script
root@piplite:/# ufw enable
Firewall started and enabled on system startup
root@piplite:/# /etc/init.d/ufw restart
* Skipping restart (not enabled)
root@piplite:/# ufw enable
Firewall started and enabled on system startup
root@piplite:/# /etc/init.d/ufw restart
* Stopping firewall: ufw... [ OK ]
* Starting firewall: ufw... iptables-restore: line 71 failed
* Problem running '/etc/ufw/before.rules'... iptables-restore: line 34 failed
* Problem running '/etc/ufw/after.rules'... [fail]
# don't delete the 'COMMIT' line or these rules won't be processed
COMMIT <-- line number 71 and 34
Thanks.