ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/C6H6N4O4/c7-8-5-2-1-4%289%2811%2912%293-6%285%2910%2813%2914/h1-3%2C8H%2C7H2/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/C6H6N4O4/c7-8-5-2-1-4%289%2811%2912%293-6%285%2910%2813%2914/h1-3%2C8H%2C7H2 could not be loaded.