ERROR opening https://cactus.nci.nih.gov/chemical/structure/COC%28%3DO%29C1%3DCOC%28C2C1CC%3DC2CO%29O/file?format=sdf&get3d=True  -- COC%28%3DO%29C1%3DCOC%28C2C1CC%3DC2CO%29O could not be loaded.