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