I observed some issues with 26.7.4 which caused Unbound to fail and therefore basically killed off my internet access.
This is a home setup so it would not likely to hit businesses that have dedicated hardware.
I run OpnSense in a Proxmox VM with 2 WAN interfaces directly bridged from the hardware into OpnSense as well as 1 LAN interface with around 8 VLAN's stacked on top of that.
By default when you instantiate a VM in a somewhat older Proxmox version, it will attach a x86_64 processor (depending on the underlying hardware). This will become incompatible with some of the later Python libraries such as NumPy which seem to require some fancy processor features that are exposed with newer processor architectures. Therefore when I changed the underlying virtual cpu to x86-64-v2 in Proxmox and rebooted the VM, that problem went away.
Another issue that I encountered was also related to Unbound.
Apparently one of the local network systems had registered with an unsupported hostname "xxxxx." (mind the . at the end) via DHCP. I didn't see this at first and just assigned a static IP address for this system in Kea without modifying the hostname. This causes that hostname to show up in the Unbound static list as well when you have Opnsense configured to do so via the "Register DHCP Static Mappings" setting.
As the "." will cause a concatenation of hostname and domainname resulting in something like "xxxx..example.com". That will cause Unbound to fail as it cannot load an empty zone "..example.com". You'll run into errors like:
```
2026-09-24T22:49:17 Critical unbound [79215:0] fatal error: Could not set up local zones
2026-09-24T22:49:17 Error unbound [79215:0] error: Bad local-data RR xxxxx..example.com IN A 10.10.10.10
2026-09-24T22:49:17 Error unbound [79215:0] error: error parsing local-data at 12 'xxxxx..example.com IN A 10.10.10.10': Empty label
```
After I corrected the hostname and registration in Kea, unbound could start normally.
Not sure if anyone has run into the same issue(s) but it may come in handy to have it posted here for future reference.
Cheers
Erwin