FAILED BINDING TO AUTHENTICATION ADDRESS * PORT 1812: ADDRESS ALREADY IN USE FREERADIUS

Failed binding to authentication address * port 1812: Address already in use
/etc/freeradius/radiusd.conf[240]: Error binding to port for 0.0.0.0 port 1812

ps aux | grep free
or
ps ax | grep radius

check for the process already running.
kill -9 PID
then start radius in debug mode.

/usr/sbin/freeradius -X you probably have one started manually and one from init.d, and they are arguing over port access.

After all, when you kill the PID.

Just start the freeradius from demon.

/etc/init.d/freeradius start

Start normally.

Now to confirm everything is working fine, restart the server.

/etc/init.d/freeradius restart