If you have been experiencing issues with the PlayStation Network, you are not alone. Users have been reporting experiencing issues while using PSN for gaming online.
Users are able to sign-in, create accounts and use certain apps, but anything related to gaming is experiencing disruptions. Sony is aware of the issues and is addressing them.
The PlayStation Service site details that nearly every PlayStation Network feature is available, except for gaming and social features on the PS4. The site details: issues related to launching games, applications, and/or social features such as trophies, messaging, or friends list.
Essentially, the most important features on PSN aren't working.
Keep track of of the issue here.