Slicer adds non-existing top layer to model (STL)

[fred_dot_u]

You may have a non-manifold model. Consider to open it in Meshmixer and use Analyze/Inspector to see what is presented. Rhino isn't the "usual" 3D modeler for 3D printing and may not prevent you from creating non-manifold models. Self-intersecting faces is another failure point for some 3D modeling software, i.e., SketchUp that will create models that won't slice properly.

[flemming89]

Thanks for the reply, I did not know of that tool.
I ran the inspector i MM, which did reveal a lot of flaws. It did however recognize the hole in the model as it should be, so I still don't know why CURA wants to print over the hole. Maybe it is simply a poor model, as it was exported from a building model not made for 3D-printing.
2019-01-20 09_37_06-Autodesk Meshmixer - Kiosk_E00_v2.stl.jpg