Fatal trap 12 after enabling a firewall on FreeNAS 8.3.1 (x64)

[Taeke Boersma]

Currently I am trying to use a firewall (pf.ko) on FreeNAS version 8.3.1 (x64). I thought this would be a rather simple operation, however after rebooting the machine I get a "Fatal trap 12: page fault while in kernel mode"

Below the minimum steps needed to reproduce this issue:

Installed FreeNAS 8.3.1 (x64) on a Vmware virtual machine, configured an IP address and default gateway. Then added the pf_enable="YES" to the /conf/base/etc/rc.conf file and created a simple pf.conf file in the same directory.

pf.conf
block in all
block out all

After a reboot of the machine, I get "Fatal trap 12: page fault while in kernel mode"

Please help!