Unfortunately, the PS Network has been offline for the past several hours. This will result in numerous problems/error codes when you're trying to do anything with your PS4 (or other Sony video game consoles) that require the PS Network - such as signing into your account.
Sony has stated that "due to extremely high volume, users may experience intermittent connection issues. We are actively working to resolve the situation".
YOU CAN EASILY CHECK THE STATUS OF THE PS NETWORK HERE: https://support.us.playstation.com/app/answers/detail/a_id/237
We just need to be patient with Sony & give them as much time as they need to fix up the PS Network.
I've been having the same problems ALL day Sunday, Nov 17th. I called Sony CS and they said that PSN was partially down in some areas, and that it would definetly be back late afternoon. Well it is now midnight and I'm still having the same problem. If the problems persists through tomorrow, I might consider returning the PS4!!