Auto Config Backup fails with unknown error

Kenni

I've noticed over the past couple of months that when I log into pfSense CE v2.8.1, there's often a notification with the following error:

At the same time I see that the size of many recent backups are listed to be 0 B in size:

The "Current" backup is listed to be 134 KiB, but if I manually trigger a "Backup Now" or do some other changes which causes a new backup to be initiated, the backup that was previously "Current" changes its displayed size to 0 B, while the new "Current" is now listed to be 134 KiB.

However, if I click on download on any of the 0 B configuration backups, it downloads a file with a ~134KiB file size - mostly pointing towards this just being a display issue - but that doesn't explain the unknown error in the notification.

Any idea of what is going on, or what I can do to help debug the issue - or at least just reset all the ACB configuration and start from scratch?

Thanks.

stephenw10

I assume it doesn't fail with errors every time? Like you don't see new errors if you run a manual backup?

Kenni

@stephenw10 Yes, that seems to be the case. I just tested with a manual backup and it did not trigger any error notification.

stephenw10

Hmm, OK. Do you see anything else logged at the time of the failure? A DNS issue perhaps?

Kenni

@stephenw10 So it happened again today, it seems to be related to pfSense stopping to resolve DNS for its internal queries. I've experienced this a couple of times during the past 6 months. So while all LAN clients continue to be able to resolve DNS by querying the LAN IP of pfSense, pfSense itself cannot resolve any DNS names:

I've looked at all of the logs in the System Logs section, but I do not see any errors beside the failing filterdns logs shown above. Rebooting pfSense "fixes" the issue.

stephenw10

How do you have the DNS behaviour configured in System > General setup?

Are LAN clients using Unbound in pfSense for DNS?

Kenni

@stephenw10 The configuration looks like this:

Regarding Unbound, then yes, I would assume so (?). DNS Forwarder is not enabled, while DNS resolver is enabled. Clients are served with the IP address of one DNS server through DHCP, which is the LAN IP of pfSense.

stephenw10

Hmm, one of those should always respond if it can be reached.

Next time it fails I would try to dig@ it directly from the CLI like:

[26.07-RELEASE][root@4100-3.stevew.lan]/root: dig @1.1.1.2 acb.netgate.com

; <<>> DiG 9.20.23 <<>> @1.1.1.2 acb.netgate.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19781
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;acb.netgate.com.               IN      A

;; ANSWER SECTION:
acb.netgate.com.        300     IN      A       208.123.73.69

;; Query time: 236 msec
;; SERVER: 1.1.1.2#53(1.1.1.2) (UDP)
;; WHEN: Thu Aug 27 12:55:06 BST 2026
;; MSG SIZE  rcvd: 60

Either DNS traffic is being blocked somehow or you have some general connectivity issue I'd guess.

NOCling

My 2100 works, but I have the same problem with my 6100, even if i try to run a manual backup.

DNS works, if i try to resolve from the pf itself.
I renew all keys, push in the encryption key again, nothing works.

An error occurred while uploading the encrypted Netgate pfSense Plus configuration backup to https://acb.netgate.com (60) @ 2026-08-28 02:03:07
An error occurred while uploading the encrypted Netgate pfSense Plus configuration backup to https://acb.netgate.com (60) @ 2026-08-28 18:26:00

Kenni

@NOCling Sounds like a different issue when you also experience it on manual backups + your DNS is working + you get a different error message (“60” instead of “Unknown error”). Probably better with a new thread instead of mixing two different issues together.

stephenw10

Yup that looks more like a cert problem. Better to open a new thread.