ERROR opening https://cactus.nci.nih.gov/chemical/structure/C/C%28%3DC%5CCNC1%3DNC%3DNC2%3DC1NC%3DN2%29/CO/file?format=sdf&get3d=True  -- C/C%28%3DC%5CCNC1%3DNC%3DNC2%3DC1NC%3DN2%29/CO could not be loaded.