ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCN%28CC%29CCc1c%28C%29%5BnH%5Dc2ccccc12/file?format=sdf&get3d=True -- CCN%28CC%29CCc1c%28C%29%5BnH%5Dc2ccccc12 could not be loaded.