ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC1C%28C2%3DCC%3DCC%3DC2%29OC%28N%29%3DN1/file?format=sdf&get3d=True  -- CC1C%28C2%3DCC%3DCC%3DC2%29OC%28N%29%3DN1 could not be loaded.