In this post, we are going to talk about the dumbest problem on the PS4 system – error NP-31730-4, which means you are logged out of PSN. The solution to error NP-31730-4 is elementary – just re-enter the network. That’s all!
To enter the PlayStation Network, you need to select in the menu item [Settings] and go to [PSN], then click on [Sign in to PSN]. Please note that there may be scheduled maintenance work on the PlayStation Network that will prevent you from logging in. PSN server status can be checked on this.
If you cannot solve error NP-31730-4, please contact the PlayStation 4 technical support service accordingly. As you can see, there is not much material to fix this problem, but the error itself is not as bad as it seems.