ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BCs%2B%5D.%5BCs%2B%5D.%5BO-2%5D/file?format=sdf&get3d=True -- %5BCs%2B%5D.%5BCs%2B%5D.%5BO-2%5D could not be loaded.