ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BnH%5D1cncc1C1%28Cc2c%28C1%29cccc2%29CC/file?format=sdf&get3d=True  -- %5BnH%5D1cncc1C1%28Cc2c%28C1%29cccc2%29CC could not be loaded.