ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC1%3DCC%28%3DC%28C%3DC1%29NC2%3DNCCN2%29Cl/file?format=sdf&get3d=True -- CC1%3DCC%28%3DC%28C%3DC1%29NC2%3DNCCN2%29Cl could not be loaded.