ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%28NCC%29CC1%3DCC%28C%3DCO2%29%3DC2C%3DC1/file?format=sdf&get3d=True  -- CC%28NCC%29CC1%3DCC%28C%3DCO2%29%3DC2C%3DC1 could not be loaded.