why the export in stl is not done as before see pictures
should I reinstall 3Dslicer
It looks like the surface normals are inside out. Perhaps you applied a transform to the model in Slicer that turned the model inside out. Anyway, you can always recompute/reorient normals in Surface Toolbox module.
Always use the latest version of Slicer. In general, use the latest Slicer Stable Release, but if you need some most recent feature or fixe then the latest Slicer Preview Release.
Thanks a lot
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