Why does Safari keep telling me to force reload pages?

Every time I am on Facebook on Safari, I get the pinwheel and Safari freezes up. It then tells me to force reload pages, and I have to hit "visit page" in order to make them all work again. This continues to be an issue even though I have done all available updates to mac and safari, and cleared my stored website data and history. I'm out of ideas. It doesn't seem to matter if I have one tab open or 40, as long as I'm on Facebook it will freeze up. What's going on?