Your .iso.gz is compressed. You must decompress it first:
gunzip pfSense-CE-2.8.0-RELEASE-amd64.iso.gz
Then write the .iso to USB (e.g., with dd, Rufus, or BalenaEtcher). pfsensece280releaseamd64isogz upd
Netgate’s official guide:
🔗 How to Install pfSense on USB Flash Drive Then write the
Cause: You wrote the ISO in legacy BIOS mode but attempted to boot UEFI, or vice versa. Fix: Re-write the USB stick. In Rufus, explicitly choose "UEFI (non-CSM)" for modern motherboards, or "MBR (Legacy)" for older ones. Cause: You wrote the ISO in legacy BIOS
Under System > Advanced > Admin Access, check the "PHP-FPM" settings. Old custom pools may be ignored.