ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC1%3DNC%3DCN1CC2CCC3%3DC%28C2%3DO%29C4%3DCC%3DCC%3DC4N3C/file?format=sdf&get3d=True  -- CC1%3DNC%3DCN1CC2CCC3%3DC%28C2%3DO%29C4%3DCC%3DCC%3DC4N3C could not be loaded.