ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%26%2361%3B%26%2391%3BU%26%2393%3B%26%2361%3BO.F.F/file?format=sdf&get3d=True -- O%26%2361%3B%26%2391%3BU%26%2393%3B%26%2361%3BO.F.F could not be loaded.