ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC1%3DCC%28%3DC2CC%28CC2%3DC1OC%29N%29OC/file?format=sdf&get3d=True  -- CC1%3DCC%28%3DC2CC%28CC2%3DC1OC%29N%29OC could not be loaded.