ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/2C3H6O2.Ca/c2%2A1-2-3%284%295/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/2C3H6O2.Ca/c2%2A1-2-3%284%295 could not be loaded.