ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/C6H12N2/c1-2-8-5-3-7%281%294-6-8/h1-6H2/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/C6H12N2/c1-2-8-5-3-7%281%294-6-8/h1-6H2 could not be loaded.