ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28OCC%29%5BC%40%40H%5D%28N%29CCCNC%28N%29%3DN/file?format=sdf&get3d=True  -- O%3DC%28OCC%29%5BC%40%40H%5D%28N%29CCCNC%28N%29%3DN could not be loaded.