You could try downloading the newer version of slic3r by itself and generate the gCode from it.  you wouldn't have to download the new RH.  Might be something to see.

Meshlab allows for a full see-through wireframe view.  There were no non-manifold edges that I could see and no self-intersecting facets (per Meshlab's selection function).  I would have re-worked the mesh to be more quads than triangles, but Sketchup doesn't really give you that option.

Still, you don't see meshes this clean that often.  I ran it through Slic3r .99 on RH .90b and it sliced fine.  64 layers, about 19 minutes print time... I re-iterate:  A clean model.

Oh I wasn't meaning to imply that I doubted you.  If I were experienced enough to think you were wrong I probably wouldn't have had the question in the first place :-D

That said, maybe it's that I'm running the version that Solidoodle bundles (RH 0.85b and I don't know what version of slic3r).  I knew there were newer versions but I was trying to stay as close to "stock" for the time being to try and reduce the opportunities for errors while I get settled in with my machine.

Still, you don't see meshes this clean that often.  I ran it through Slic3r .99 on RH .90b and it sliced fine.  64 layers, about 19 minutes print time... I re-iterate:  A clean model.

It's 10 posts for links.

Congrats on the model.  It's very clean.  Meshlab shows no issues with the mesh, so this has got to be a slicing issue.  Try to see what pronterface or kisslicer will do with it, but you shouldn't be having any issues.

I assume that you're building this to allow for more z-stop clearance?

Hmmm, that goes counter to what I was finding. I edited out the "tower", and rebuilt it square and it slices fine, then added the crown (or rather radius'd the corners since it was a subtraction not an addition) to the tower without issue; but as soon as I try to slope the transition from the platform to the "tower" slic3r freaks out.   Ah well, it was putting lipstick on a pig anyways; the slope wasn't going to provide much support to the "tower" at the scale it's being printed at.

And yeah; I don't actually NEED it at the moment; even with the glass-bed; but I thought it would be a quick and simple (heh) thing to model since there wasn't one on thingverse that would work for the new version of the SD3.  Compared to thing 61463; I need a "tower" for the z-stop screw to properly reach, as well as to countersink the two retaining bolts as what came on my unit are too short and would interfere with the bed otherwise.

Congrats on the model.  It's very clean.  Meshlab shows no issues with the mesh, so this has got to be a slicing issue.  Try to see what pronterface or kisslicer will do with it, but you shouldn't be having any issues.

I assume that you're building this to allow for more z-stop clearance?

I'm not looking for an  "auto-fix" like netfabb or something like that; I want to know what I screwed up while I was modeling it in the first place so I can NOT do that again.

Based upon the slicing I'm thinking the error is near where the top-most radius begins; however I've checked (and re-checked) the area and can't spot any inverted faces or holes or such although slic3r says there is a hole or "self-interfacing facets"