@tinfoilmatt A domestic router, I guess, can be called a SOHO router that the average man in the street can but from their local computing shop - Linksys, TP-Link, D-Link, Draytek, Netgear etc or is supplied by your ISP. It excludes high end devices like some of the CIsco and Juniper devices and things like that.
The warning is not good. It does not even point the user to the correct screen or give him any instructions. It did help me eventually narrow it down, but I consider myself way more advanced than your average user - I used work for Clearcenter providing support for ClearOS (which also resets the routing table when changing the external WAN settings).