Pf Configuration Incompatible With Pf Program Version

If you’ve recently updated your FreeBSD, OpenBSD, or macOS system, you might have encountered a cryptic and frustrating error when trying to reload your firewall:

If you cannot reboot (e.g., production system), you can attempt to unload the old module and load the new one. Unloading PF will flush all firewall rules and state tables, potentially opening your system to traffic. pf configuration incompatible with pf program version

If which pfctl returns /usr/local/sbin/pfctl or similar: If you’ve recently updated your FreeBSD, OpenBSD, or

He pulled up the man page on his laptop. pf.conf(5) . There it was, buried in the "Migration Notes" for 7.5: If you’ve recently updated your FreeBSD

PF cannot be unloaded if it is in use (e.g., rules are active). If you have a zombie configuration, even kldunload pf may fail. In such cases, the mismatched module persists.