ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCC%28C%29NCC%28C1%3DCC2%3DC%28CCCC2%29C%3DC1%29O/file?format=sdf&get3d=True  -- CCC%28C%29NCC%28C1%3DCC2%3DC%28CCCC2%29C%3DC1%29O could not be loaded.