ERROR opening https://cactus.nci.nih.gov/chemical/structure/COC1%3DCC%28%3DCC%28%3DC1OC%29OC%29C%3DO/file?format=sdf&get3d=True  -- COC1%3DCC%28%3DCC%28%3DC1OC%29OC%29C%3DO could not be loaded.