ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BCl-%5D.%5BCl-%5D.%5BFe%2B2%5D.NC%28%3DO%29c1cccnc1.NC%28%3DO%29c2cccnc2/file?format=sdf&get3d=True  -- %5BCl-%5D.%5BCl-%5D.%5BFe%2B2%5D.NC%28%3DO%29c1cccnc1.NC%28%3DO%29c2cccnc2 could not be loaded.