ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C15H20N4/c1-8-3-10(14(18)6-12(8)16)5-11-4-9(2)13(17)7-15(11)19/h3-4,6-7H,5,16-19H2,1-2H3/file?format=sdf&get3d=True  -- InChI=1S/C15H20N4/c1-8-3-10(14(18)6-12(8)16)5-11-4-9(2)13(17)7-15(11)19/h3-4,6-7H,5,16-19H2,1-2H3 could not be loaded.