ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/N4S4/c1-5-2-7-4-8-3-6-1/file?format=sdf&get3d=True  -- InChI=1S/N4S4/c1-5-2-7-4-8-3-6-1 could not be loaded.