ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1/C3H4O4/c4-1-2(5)3(6)7/h4H,1H2,(H,6,7)/f/h6H/file?format=sdf&get3d=True  -- InChI=1/C3H4O4/c4-1-2(5)3(6)7/h4H,1H2,(H,6,7)/f/h6H could not be loaded.