ERROR opening https://cactus.nci.nih.gov/chemical/structure/OC1%3DCC%3DCC2%3DC1C%28CCN%28C%29CCC%29%3DCN2/file?format=sdf&get3d=True  -- OC1%3DCC%3DCC2%3DC1C%28CCN%28C%29CCC%29%3DCN2 could not be loaded.