This error may be occurring due to a problem on the server side. Please try the following:
- Check PlayStation® status page to see if there are any server failures or if maintenance is in progress.
- This may be a temporary issue. Please try again after a while.
- While you wait, please update your system software to the latest version from Settings > System > System Software > System Software Updates and Settings.
- Turn off your router, wait at least 5 minutes, then turn it back on.