ERROR opening https://cactus.nci.nih.gov/chemical/structure/C2%28C%3DC3%29%3DC1C3%3DCC%3DC1C%3DC2/file?format=sdf&get3d=True  -- C2%28C%3DC3%29%3DC1C3%3DCC%3DC1C%3DC2 could not be loaded.