ERROR opening https://cactus.nci.nih.gov/chemical/structure/C%5BC%40%5D3%28c2nc1c%28C%28N%29%3DO%29cccc1%5BnH%5D2%29CCCN3/file?format=sdf&get3d=True  -- C%5BC%40%5D3%28c2nc1c%28C%28N%29%3DO%29cccc1%5BnH%5D2%29CCCN3 could not be loaded.