Its difficult to fix these issues as pfBlockerNG is a package and not tightly woven to pfSense… When pfSense is rebooted or if the box loses power, the package doesn't see the event and has no way to remove this line from the Unbound Adv settings:
server:include: /var/unbound/pfb_dnsbl.conf
So your best bet, is to remove that line and save the Resolver settings. Then reboot. If it reboots and the file pfb_dnsbl.conf is missing, unbound will not start and cause other issues.