Blender Library Issues

Hello. I hope someone can help me. I feel very dumb about this, and usually do ok with all things blender related without having to ask for help, as there’s loads of support out there. However, I can’t get the blender library to work. I downloaded the file, put it in my scripts folder, and the option came up in the script window. But when I select an object and try to add it to the library, I get a python error / check console message. I think maybe I haven’t understood the concept properly or I am just being a noob. Could someone possibly explain it to me step by step as one might to small child with ADHD?
Thanks a bundle.