ERROR opening https://cactus.nci.nih.gov/chemical/structure/C%5BN%2B%5D%28C%29%28CCC1%3DCNC2%3DCC%3DCC%3DC21%29%5BO-%5D/file?format=sdf&get3d=True -- C%5BN%2B%5D%28C%29%28CCC1%3DCNC2%3DCC%3DCC%3DC21%29%5BO-%5D could not be loaded.