Facebook definitely changes things frequently. We work very hard to keep things up to date, as simple as can be, and somewhat standard (so you don't have to know the underlying changes that Facebook has made).
I replaced the module to "SCSocialWidget module" but it doesn't show up. I think my module settings are ok but nothing shows up.
Module assignments on all pages.
I don't see anything on your site that indicates the module is attempting to appear at the bottom. Do you have any other modules in that position? Can you try it in any other positions to test? Beyond that, I'd try re-create the SCSocialWidget module to see if that fixes it somehow.
I hope that helps, but if you need anything else, just let us know.
Thanks,
Alex