ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC12C3CCC%28C1%28C%28%3DO%29OC2%3DO%29C%29O3/file?format=sdf&get3d=True -- CC12C3CCC%28C1%28C%28%3DO%29OC2%3DO%29C%29O3 could not be loaded.