Help I can messages to people but they can not reply

How weird. Sometimes this is in privacy settings (unfortunately, FB changes things all the time, and it changes them in waves, so one person's settings often don't match another's). Have you tried with people who you have listed as the folks whose posts you want to see first? Or with anyone you're in a relationship with if it's on Facebook, you might try with them. Basically, I am suggesting people where the program gets strong social signals that you don't have them blocked.

Also, try having people message you first, or older message streams, and see if they can reply.