I have tried this option
sudo gedit /etc/dbus-1/system.d/org.freedesktop.UPower.conf
and change setting
<allow send_destination="org.freedesktop.UPower.KbdBacklight" send_interface="org.freedesktop.DBus.Properties"/>
i have changed tag
<deny> but it didn't work.
Second option i have tried below command on terminal
xset led 3
This command not work for me. Please help me out from this unnecessary bug.