every time i hit A to preview this as a mesh, ZBrush crashes (see attached crash report text file & feel free to also try out the attached ZTL file).
(i assume this has something to do with some hard coded path stuff that doesn’t like that i’ve moved the application to a place of MY choosing)
Your ZSphere model is not clean enough for ZBrush to skin. This is causing the crash when you press ‘A’.
The main problem is that the head ZSphere is too close to the body. Whenever you have two ZSpheres you should be able to see at least one connector sphere between them.
There are also problems with the legs. This is indicated by the transparent connector spheres. This shows that the skinning won’t be good at that point (though this shouldn’t cause a crash). You should move the nearest leg ZSpheres away from the body a little so that the connector spheres appear solid.
I’ll report the file load error to the development team.
Here’s a reworked version of the file.
thank you very much Marcus. i appreciate your assistance and the explanation (i thought the transparent parts of the ZSphere was another bug like the “Show Sketch” bug, and therefore ignored it).
i do hope the developers can make ZBrush’s skinning failure more graceful. if it basically gave me a message like “[insert what you said above], please adjust your model accordingly and try skinning again,” that would be a lot easier to deal with (and cause less people to ask you about it, because i can’t imagine i’m the first… right? :lol: ).
but now i can get back to it, so thanks very much! 
PS: thanks extra for the adjusted ZTL file