Comment 2 for bug 1634462

Also shows up here: https://ubuntuforums.org/showthread.php?t=2351896

In reviewing the above proposed "solution", I found these anomalies:
usr/share/icons/Lubuntu/index.theme refers to "...Humanity/192..."
usr/share/icons/lubuntu/index.theme does not (N.B. "L" vs "L")

Also, usr/share/icons/Lubuntu/imported-Humanity/192 only has one (yelp) icon whereas
usr/share/icons/Lubuntu/imported-Humanity/48 has many (as do /32 ...)

Also, usr/share/icons/lubuntu/ (lowercase "l") only has index.theme and no other files.

I've seen the same error message for several other applications incuding vlc.

I'm relatively new to linux and don't really know how the above is supposed to work, but this seems likely relevant to maintainers.