ERROR opening https://cactus.nci.nih.gov/chemical/structure/C1%3DC2C%28%3DCC%3DC1%29C%28%3DC%5BN%5D2C%29C/file?format=sdf&get3d=True  -- C1%3DC2C%28%3DCC%3DC1%29C%28%3DC%5BN%5D2C%29C could not be loaded.