Source: http://apple.stackexchange.com/questions/151345/vpn-client-is-not-working-after-yosemite-update-enforce-firewall-policy-fail
Solution: put computer into kext developer mode (-> 10.9 behavior)
sudo nvram boot-args="kext-dev-mode=1"
To change back to 10.10 behavior (VPN client will not work)
sudo nvram -d boot-args
After the change, you need to reboot the computer
