ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC1%3DCNC%28%3DC1C%28%3DO%29OC%28C%29C2%3DCC/file?format=sdf&get3d=True -- CC1%3DCNC%28%3DC1C%28%3DO%29OC%28C%29C2%3DCC could not be loaded.