ERROR opening https://cactus.nci.nih.gov/chemical/structure/CN%28CCC1%3DCNC2%3DCC%3DCC%3DC21%29CC%3DC/file?format=sdf&get3d=True  -- CN%28CCC1%3DCNC2%3DCC%3DCC%3DC21%29CC%3DC could not be loaded.