ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC1%3DNOC%28%3DC1%29%5BC%40%40H%5D2CCCN2C/file?format=sdf&get3d=True -- CC1%3DNOC%28%3DC1%29%5BC%40%40H%5D2CCCN2C could not be loaded.