Error code NW-31456-9 refers to a large series of “NW” failures that typically indicate a network failure. However, in the case of this problem, there is not a huge variety of solutions. I had to explore the forums in search of those actions that caused a positive result from other users. Error NW-31456-9 can appear when launching a game, connecting to game servers, or logging into the PlayStation 4. We’ve managed to select a number of fixes that have received positive feedback from users who have tried them.
How to fix error NW-31456-9 on PS4?
In advance, you need to exclude 2 common problems: random system crashes (by restarting the console) and unavailability of PSN servers (link to check service status). After making sure that the cause is not in these breakdowns, you can proceed to more precise fixes.
Method 1: re-login to PSN account
You should try to log out of your PlayStation account on the console, then turn off the console for a few seconds, restart it and log in again.
Method 2: change MTU settings
Some users claim that they managed to fix this failure by setting the MTU to 1473. We also recommend that readers try this method.
What do we have to do:
- Press the PS key on the controller to go to Settings.
- Open the “Network” tab and select “Configure Internet Connection”.
- Select the type of network and click on the “Manual” option.
- Specify 1473 for MTU value.
- Leave the rest of the settings as they were.
Method 3: change DNS
By analogy with the previous method, you should change the DNS settings, setting the primary server to 188.8.131.52, and the backup server to 184.108.40.206.
The last option available is to factory reset your PS4, but hopefully it won’t come to that. For now, that’s all we can offer to fix the NW-31456-9 crash.