Date: 2018feb28 OS: Linux Product: dnsmasq Q. dnsmasq: illegal repeated keyword at line N of /etc/dnsmasq.d/caching-dns.conf A. This happened to me because an update of dnsmasq started to read

/etc/dnsmasq.conf and then my config file... /etc/dnsmasq.d/caching-dns.conf

The second file has some keywords that were also in the first file. So the solution is to remove the repeated keyword (it as user=<user> and group=<group> for me) from one of the config files. I'm pretty sure, the second file is for localization so its probably best to make your changes there.