While some people appear to be able to get back on to the PlayStation Network, even though they were affected by today’s issues, a new error np-31970-0 has been popping up and giving them some trouble.
The new error seems to occur when the person attempts to join a party, so it is safe to say that the problems associated with today’s issues have not been fully resolved yet. The official network status checker for Playstation still shows the issues are ongoing, as well. Sony sent out a tweet earlier today to advise that they were aware of the current issues, and were working on a fix. If you are still able to get on the PSN, but not join any parties, it may just be time for some singleplayer action. That Crown of Sorrow run will have to wait just a little longer.
We’re aware that some users are experiencing issues logging into PSN. Thank you for your patience as we investigate: https://t.co/s026QGzJZr
— Ask PlayStation (@AskPlayStation) June 13, 2019
The reason errors like this such big issues is that people will worry that it is a problem with their end, either their console or their internet connection. Rest assured, this same error has happened before, and at the time it was tied into other network problems on the PSN, so this is almost certainly what is happening today.
For now, all you can do is wait for the fix that Sony has advised they are working on.