You're just as bad as him if you don't actually help the guy. Your post isn't too helpful. Nothing is wrong with him liking Renderman stuff really.
Actually, you're right. I wasn't treated like this when I was new and I had answers so I shouldn't go around being a richard.
If you're putting them in the right directory, the problem could be the addon. If you're on a mac like I am, and using Safari, you're likely to have the "automatically decompress safe files" option on; that can sometimes lead to files being unzipped and thus becoming unusable. Also, I'm not on a PC so I don't know, but I think it should be in steamapps/common/blockland/addons or if you can't find that, in the Documents-located folder. If you're putting it in there I don't know how to help him.