ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C6H12N4/c1-7-2-9-4-8(1)5-10(3-7)6-9/h1-6H2/file?format=sdf&get3d=True  -- InChI=1S/C6H12N4/c1-7-2-9-4-8(1)5-10(3-7)6-9/h1-6H2 could not be loaded.