ERROR opening https://cactus.nci.nih.gov/chemical/structure/CN%28C%29C%28C1COCOC1%29C2%3DCN%3DCC%3DC2/file?format=sdf&get3d=True  -- CN%28C%29C%28C1COCOC1%29C2%3DCN%3DCC%3DC2 could not be loaded.