. If you have installed a different version via Homebrew or MacPorts, it might be trying to load rules the kernel doesn't understand. Check your path with: which pfctl Revert to Default
. This is most common in FreeBSD-based environments (like pfSense or OPNsense) following a partial update or a custom kernel build. Key Causes & Context Kernel vs. Userland Mismatch firewall is implemented in the kernel, but the pf configuration incompatible with pf program version
Using source (for advanced users):
To view the kernel's exported version:
If you recently upgraded the kernel without updating userland, perform a complete upgrade. provides step-by-step diagnostic procedures
This article delves deep into the causes of this error, provides step-by-step diagnostic procedures, and offers permanent solutions to ensure your firewall operates smoothly. pf configuration incompatible with pf program version