ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%26%2361%3B1S/C2H4N4/c3-2-4-1-5-6-2/h1H%2C%28H3%2C3%2C4%2C5%2C6%29/file?format=sdf&get3d=True  -- InChI%3DInChI%26%2361%3B1S/C2H4N4/c3-2-4-1-5-6-2/h1H%2C%28H3%2C3%2C4%2C5%2C6%29 could not be loaded.