improper switch off pfsense device by unplug power plug is highly not recommended.
specially during setup, configuration, update, update defense rules ... etc, some files may be corrupted.
go to WebGUI as below path ...
- WebGui-> Diagnostics -> Halt System : switch off
- WebGui-> Diagnostics -> Reboot : reboot device
please call us for support if you have boot up problem, We have firmware recovery USB