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