ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/C5H6N2/c6-5-2-1-3-7-4-5/h1-4H%2C6H2/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/C5H6N2/c6-5-2-1-3-7-4-5/h1-4H%2C6H2 could not be loaded.