Which FreeRADIUS package are you using, the 2.x package or the 3.x package? If you are using the 2.x package, remove it and then install the 3.x package.
Also, you appear to be running a MySQL server on the firewall itself ("Attempting to connect to radius@localhost:3306/radius") which is not possible unless you made unsupported manual changes to the firewall packages or installed a package from an outside source, which may have compromised/broken your installation in some way, leading to the error you see.