Facebook problem on my first generation iPhone?

Yeah, I know the first generation iPhone is old but! I have a problem with my facebook.
I was messaging my friend through facebook, using my iPhone and suddenly! It told me that the message couldn't be sent. I logged off and went back on. I went to check my messages and it says error and in highlighted in blue try again and
I tap the highlighted lettering and nothing happen. I don't know how to fix this problem. I refresh many times. And nothing is working. What should I do.

Don't freak out, it's happening to a bunch of us. I think they are updating and it's a bug from the update.
You can't really do anything, just have to wait it out.