ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/Cl2O4/c1-6-2%283%2C4%295/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/Cl2O4/c1-6-2%283%2C4%295 could not be loaded.