ERROR opening https://cactus.nci.nih.gov/chemical/structure/COP%28%3DS%29%28OC%29SCn1nnc2ccccc2c1%3Ao/file?format=sdf&get3d=True  -- COP%28%3DS%29%28OC%29SCn1nnc2ccccc2c1%3Ao could not be loaded.