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