ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C16H20N4O2/c17-13-1-3-14(4-2-13)18-19-15-5-7-16(8-6-15)20(9-11-21)10-12-22/h1-8,21-22H,9-12,17H2/b19-18 /file?format=sdf&get3d=True  -- InChI=1S/C16H20N4O2/c17-13-1-3-14(4-2-13)18-19-15-5-7-16(8-6-15)20(9-11-21)10-12-22/h1-8,21-22H,9-12,17H2/b19-18  could not be loaded.