I don't seem to have the option Null block (logging)

Go to Firewall > pfBlockerNG > DNSBL and make you you use :

and also :

@Doody

If a LAN device "92.168.1.84"can't even ping "192.168.1.1" (pfSense, right ?), and you think it's pfBlocker ... that's quiet impressive.

Well it seems more than a coincidence that I had to power cycle my router and then was unable to access the web interface of my Pfense router as it was blocked by PfblockNG even though I had made no changes to any config.

I do use IP feeds

So it's highly possible that this IP address had been added during a blocklist update.

Thanks I will compare the config.

pfBlockerNG 3.2.8
pfsense 2.8.1-RELEASE (amd64)

I don't seem to have the option Null block (logging)

If a LAN device "92.168.1.84"can't even ping "192.168.1.1" (pfSense, right ?), and you think it's pfBlocker ... that's quiet impressive.

Visiting the pfSense web GUI, using "http://192.168.1.1" and you this :

isn't normal at all.
Best solution : have a talk with the admin. I don't know what he doing, but we all agree that he might do it's job a bit better ( )

As usual :
What pfSense version ? pfBlockerng version ?
The fact that IP(s) (and not host names) are blocked, this means you have IP settings (feeds, etc) :
This page :

and the IPv4, IPv6 etc pages.

If, by accident, you use a IP feeds that contains "192.168.1.0/24" and you have pfBlockerng filter your LAN, then, yeah, that will be an issue.
This is just an example of course, IP feeds shouldn't contain RFC1918. networks.

Shows also your :

settings.

My personal advise : use Null blocking :

@Doody said in pfBlockerNG blocked access to pfsense:

What's the best way to determine what happened here and resolve the problem so I can re-enable PfblockNG?

Compare the config you used 'before' and the current one.
The differences will be minor, and all pfBlockerng settings will explain the 'why'.

Go here : Diagnostics > Configuration History and you see there is a GUI tool just for that.
( I never used it myself ^^ )