Rhino and grasshopper don't export to stl for print 3d

I have a problem exporting the 3d model from rhino to 3dprint since it does not fully materialize the model when I bake a layer from grasshopper, so the only thing that does materialize the model is the grasshopper operation but when that happens the rhino model has problems to materialize and export to stl, why does that happen? Maybe someone can help me to export the model with rhino and grasshoper, since I have attached the image where the glass made in rhino shows a hole in the bottom of the glass, I don’t know why it happened after baking a layer in grasshoper. Thank you very much, I attached the images,





looks like you need to add wall thickness or an interior surface to make it a closed volume.