[UPDATE] According to the PSN Status, the issue Sony experienced has now been resolved and PSN is currently all green.
Sony is currently experiencing a PlayStation Network outage which they are attributing to “external factors”.
Sony has confirmed the technical issue on the PSN Status website which categorises the issue as Gaming and Social and affects both PlayStation 3 and PlayStation 4
You may be experiencing issues related to launching certain games or game functionality. This is due to factors external to PSN. We are tracking the progress of the resolution of the issue.
Sony is currently working on getting the issue resolved