As a user, I'd expect an error telling me at least the file name and the line
number of the error location, preferably also the string that could not be
parsed.
Here I can only guess that it's
inet6 fe80::5054:ff:fe71:ac02/64
^^
just 2 hex digits, not 4 as expected
On my Leap 15.5, I already have 4 files /etc/sysconfig/network/ifcfg*. At least
pointing the user to that directory and the ifcfg* files there would be
helpful.