ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC/2Oc1cc%28O%29c%28O%29cc1%5CC%3DC%5C2/file?format=sdf&get3d=True -- O%3DC/2Oc1cc%28O%29c%28O%29cc1%5CC%3DC%5C2 could not be loaded.