ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/C6H8N2/c7-5-3-1-2-4-6%285%298/h1-4H%2C7-8H2/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/C6H8N2/c7-5-3-1-2-4-6%285%298/h1-4H%2C7-8H2 could not be loaded.