ERROR opening https://cactus.nci.nih.gov/chemical/structure/C1%3DC%5BCH-%5DC%3DC1.C%3D1C%3DC%5BCH-%5DC1.%5BFe%2B2%5D/file?format=sdf&get3d=True  -- C1%3DC%5BCH-%5DC%3DC1.C%3D1C%3DC%5BCH-%5DC1.%5BFe%2B2%5D could not be loaded.