Checking my dns enabled I got error too, but in my case the sites resolve normally. Although I setup the dns in my wired local machine instead of ipfire, wifi takes dns from dhcpd in ipfire whitout problems.
I don’t know say if this appears after the upgrade to core 160.
If you place your mouse pointer over the word Error you will get a pop-up that gives the error message. You can look in the System Logs under unbound on the WUI or grep /var/log/messages for unbound on the console and see what the logged error messages are.
If there is no entry against a second IP address then it means that the hostname is the same for both IP’s.
Some DNS Server providers use the same hostname for both IP’s and others use a different hostname for each IP.