Installing Linux Lite on VirtualBox Virtual Machine / MacOS ?

[Moltke]

That's what I had tried to do, as I remembered doing years ago, but it gave several errors as per the zipped jpeg. As explained, the reply in that thread on MacRumors was telling the poster to do it from the guest instead. Which also seemed a bit strange to me.

All I can see in the jpeg is what seems to be a guest additions install process failed, no "vbox extpack", was this on the host or the guest? Cause it's not clear really. Also, Linux Lite's based on Ubuntu 20.04 and you're using VBox 4.3.40 which is quite old (2016),so there may be some compatibility problems there since the error reads unknown X windows system installed. You haven't mentioned which "vbox extpack" version you're using, I guess is 4.3.40 but it'll help if you clarify that for us. Finally, you might have a better informed answer at the VBox forum https://forums.virtualbox.org/viewforum.php?f=8 since they surely know a lot more than any of us how their software works