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