ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C4H7N/c1-2-3-4-5/h2-3H2,1H3/file?format=sdf&get3d=True  -- InChI=1S/C4H7N/c1-2-3-4-5/h2-3H2,1H3 could not be loaded.