Unbound crashes randomly

[Panja]

Since a few weeks my DNS resolver/Unbound has been crashing randomly.
There has been no config change in the past weeks and the logs show me the following:

Sep 7 02:00:25	unbound	67518:0	fatal error: Could not read config file: /unbound.conf. Maybe try unbound -dd, it stays on the commandline to see more errors, or unbound-checkconf```
Sep 7 02:00:25	unbound	67518:0	notice: Restart of unbound 1.10.1.
Sep 7 02:00:25	unbound	67518:0	info: server stats for thread 3: requestlist max 0 avg 0 exceeded 0 jostled 0

Doing an Unboundconfigcheck there are no errors:

unbound-checkconf: no errors in /usr/local/etc/unbound/unbound.conf

Any one have a clue what the problem could be?
Restarting the device did not solve the problem.
Running pfSense 2.4.5-RELEASE-p1 (amd64) with the following packages:
pfBlockerNG (DNSBL has been disabled, only using to block IP's) and OpenVPN client export.

[kiokoman]

maybe try a fsck on the file system
https://docs.netgate.com/pfsense/en/latest/hardware/forcing-a-filesystem-check.html

[Panja]

Ok, thanks! Just done a check.
Is there anywhere I can look for the results?