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