ERROR opening https://cactus.nci.nih.gov/chemical/structure/COC1%3DCC%28CC%28C%29NC%29%3DCC2%3DC1OCO2/file?format=sdf&get3d=True  -- COC1%3DCC%28CC%28C%29NC%29%3DCC2%3DC1OCO2 could not be loaded.