ERROR opening https://cactus.nci.nih.gov/chemical/structure/C%28%26%2361%3BO%29%28C%28%26%2361%3BO%29O%29O.%26%2391%3BSn%26%2393%3B/file?format=sdf&get3d=True  -- C%28%26%2361%3BO%29%28C%28%26%2361%3BO%29O%29O.%26%2391%3BSn%26%2393%3B could not be loaded.