There are a few reasons why your Norton security software may be showing your subscription as expired while it is not.
In some cases, users buy a new product instead of renewing it. In some other cases the installed software cannot query the server properly because of network/Internet connection problems or simply because a user is not signed in.
Here is what can be done from a user’s side in order to try fixing this subscription expiration problem:
Open your currently installed Norton Security software and click the Help link in the upper right corner, and then Subscription Status link in the opened sub-menu.
Be sure that you’re signed into your Norton Account prior clicking onto the Subscription Status link. Above the Help link, there should be either Sign In link (if not signed in), or the name under which the Norton product has been registered (Hello, Your Name).
Sign into your Norton Account (go to https://manage.norton.com/) and click Download Norton link/button. Follow the on-screen instructions and open the file to start the installation process. Continue following the on-screen instructions.
If none of the above helps, contact Norton Support.