ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BCu%2B2%5D.%5BO-%5DC%28%3DO%29c1ccccc1.%5BO-%5DC%28%3DO%29c2ccccc2/file?format=sdf&get3d=True  -- %5BCu%2B2%5D.%5BO-%5DC%28%3DO%29c1ccccc1.%5BO-%5DC%28%3DO%29c2ccccc2 could not be loaded.