Ok, for solving this problem do some steps:
1. Logout via tweak T-3
2. It will open black screen with 2 buttons, press on FB
3. Press "Authorize" and it will open login screen
4. Press "Try alternative authorisation way" it below the pass line.
5. Now insert your username and pass and press ok. You will get message that it authorised.
6. Go to status bar and press FB button, write your message and press send.

Probably fb changed something and only this way you can authorize.
I also have this problem.. Also, i don't know why, but it have something like timeout, and sometimes you need authorize again.