pfsense ERROR – pfctl: DIOCXCOMMIT

There were error(s) loading the rules: pfctl: DIOCXCOMMIT: Device busy – The line in question reads [ 0 ]

Here’s what worked for me:
Rather than allowing your NICs to autoselect speed, duplex and flow control, I locked these in on each interface to the highest possible setting and configured the firewall to be the master controller of these settings.

In my case that’s 1000baseT full-duplex,flowcontrol,master

C’est tout.
=)D

~ Eternal Sojourner ~