ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3D%5BU%5D1%28%3DO%29O%5BMg%5DO%5BU%5D%28%3DO%29%28%3DO%29O1/file?format=sdf&get3d=True  -- O%3D%5BU%5D1%28%3DO%29O%5BMg%5DO%5BU%5D%28%3DO%29%28%3DO%29O1 could not be loaded.