ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%28C%29NCC%28C1%3DCC2%3DCC%3DCC%3DC2C%3DC1%29O/file?format=sdf&get3d=True -- CC%28C%29NCC%28C1%3DCC2%3DCC%3DCC%3DC2C%3DC1%29O could not be loaded.