ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/2C2H4O2.Cu/c2%2A1-2%283%294/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/2C2H4O2.Cu/c2%2A1-2%283%294 could not be loaded.