I am also getting the service unavailable on my PC. Tried my mobile app, messages is not working through the mobile app. Tried my web browser on my mobile device, not working there either. Tried with wifi and without wifi using my LTE and still no messages working. Had to have happened overnight, as I had sent a message last night around 10 pm CST I think. That potential buyer responded back, and I have that response in my email, but I can't do anything about it.
