ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%28C%29%28C%29NCC%28O%29COc1nsnc1N1CCOCC1/file?format=sdf&get3d=True  -- CC%28C%29%28C%29NCC%28O%29COc1nsnc1N1CCOCC1 could not be loaded.