ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BK%2B%5D.c1c%28cccc1%29%5BB-%5D%28c2ccccc2%29%28c3ccccc3%29c4ccccc4/file?format=sdf&get3d=True  -- %5BK%2B%5D.c1c%28cccc1%29%5BB-%5D%28c2ccccc2%29%28c3ccccc3%29c4ccccc4 could not be loaded.