ERROR opening https://cactus.nci.nih.gov/chemical/structure/C1%3DNC2%3DC%28N1COCC%28%3DO%29O%29N%3DC%28NC2%3DO%29N/file?format=sdf&get3d=True -- C1%3DNC2%3DC%28N1COCC%28%3DO%29O%29N%3DC%28NC2%3DO%29N could not be loaded.