ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%28CC1%3DCC2%3DC%28C%3DC1%29SC%3DC2%29NC/file?format=sdf&get3d=True  -- CC%28CC1%3DCC2%3DC%28C%3DC1%29SC%3DC2%29NC could not be loaded.