Why isn't facebook letting me message this one person?

[†Musicâ€]

So basically fb is working fine when I message everyone else, just not for my cousin. You see, we had this big disagreement on facebook, and we were saying yesss and noooo. We were copying+pasting big paragraphs of yes and no's and now everytime I try to message her the entire page freezes up!!
I can message anyone else fine, but when she messages me from my inbox or the side panel on fb, everything freezes up. What do I do to fix this? I even tried deleting the messages and sending a brand new one. Even that didn't work. It's really frustrating because now when it's time for serious talk we can't even message each other without it messing up/freezing.

[Lenny]

Try clearing your browsers Cookies/cache/temporary internet files

Also make sure you are actually deleting the messages completely and not just archiving them.

To permanently delete a conversation from your messages, simply open the conversation, then select "Delete Messages..." from the Actions menu.
https://www.facebook.com/help/1112292322...WjdQPe5oYH

If that does not work, try de-friending the person, and then re-adding them.