ERROR opening https://cactus.nci.nih.gov/chemical/structure/COC%28%3DO%29C1%3DCC%28N%29%3DC%28O%29C%3DC1/file?format=sdf&get3d=True  -- COC%28%3DO%29C1%3DCC%28N%29%3DC%28O%29C%3DC1 could not be loaded.