ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/2C6H8O2.Ca/c2*1-2-3-4-5-6(7)8/file?format=sdf&get3d=True  -- InChI=1S/2C6H8O2.Ca/c2*1-2-3-4-5-6(7)8 could not be loaded.