Those commands worked in the previous build but will not work now. What is concerning is the line "There is no driver selected for the device information set or element."
For some reason, the v6v4tunnel-driver/binding/whatever-its-called is not correctly installed anymore. It's actually part of netip6.inf, which is for IPv6 in general, but it doesn't seem to work anymore. No idea if this can be manually fixed. I don't know the commands. Tried reinstalling the inf-file with no success.
netcfg -v -m (optionally use "netcfg -v -m | clip" which will copy to clipboard so you can paste output to notepad)
This shows at least one line "Binding entry ignored since it is Type:5 Name:ms_tcpip6_tunnel". So, Windows somehow is aware that this tunnel exists in theory. Maybe they even disabled it intentionally, since MS says they don't want to actively support IPv6-transition mechanisms anymore and instead push people towards using native IPv6. See for yourself:
https://docs.microsoft.com/en-us/windows/deployment/planning/windows-10-1803-removed-features"6to4 has been disabled by default since Windows 10, version 1607 (the Anniversary Update), ISATAP has been disabled by default since Windows 10, version 1703 (the Creators Update), and Direct Tunnels has always been disabled by default. Please use native IPv6 support instead."
However, this doesn't mention "6in4". Or is that what "Direct Tunnels" are? In that case, it should be possible to enable it somehow.
Edit: if you need v6v4tunnel to work, DON'T update to 1803!!! Just stay on 1709.