ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC1%3DNN%28C%28%3DO%29C1%29C2%3DCC%3DCC%3DC2/file?format=sdf&get3d=True  -- CC1%3DNN%28C%28%3DO%29C1%29C2%3DCC%3DCC%3DC2 could not be loaded.