[EN] non-free repo missing from latest lxqt .iso & likely from others and older ones

[mdmarmer]

/etc/apt/sources.list.d/debian.list on latest lxqt .iso has
deb      https://deb.debian.org/debian/ unstable main contrib non-free-firmware
that is, non-free is missing.
I think this error is also there on other .iso and on older ones, probably back to when non-free-firmware was introduced.

We need non-free for codecs, etc.  -- everyone should check their sources.list to make sure it includes non-free

[eriefisher]

It in the XFCE4 versions sources.list