ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%28C1%3DCC%3DCC2%3DCC%3DCC%3DC21%29C3%3DCN%3DCN3/file?format=sdf&get3d=True -- CC%28C1%3DCC%3DCC2%3DCC%3DCC%3DC21%29C3%3DCN%3DCN3 could not be loaded.