Manifold STL file not rendering correctly

[Hertfordkc]

RtSHBracer.stl

What's wrong with this?

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The attached file renders properly in Blender and FreeCad, and is manifold. Simplify3D agrees that the file is manifold, but does not render both shells, i.e. S3D shows only a shell, and generating supports doesn't work. This is the only manifold file with which I've had a problem. Any ideas?

[bbinnard]

Here is a pic of the part in Craftware:

It looks like there is something very strange about the way you have defined the 4 holes in the top section. I'm guessing this is confusing the software about what is "inside" and what is "outside.

It also looks like you should use a tighter tolerance when generating the STL file.

[Hertfordkc]

This file is part of eNable's device libraries, so I can't address the tolerances or "weirdness" in the holes. While I can tinker with the mesh in Blender, I don't have any insight as to why S3D says it is OK but really can't work with it. I gather that you believe the geometry is poorly constructed.
This file is for the right hand. I can get around the immediate problem by loading the left hand's STL file into Blender and mirroring it. S3D works with the mirrored left hand.