Steve on 24 Oct, 2018 06:45 PM
welcome to the GPGTools support platform. Sorry you are having problems using GPG Suite.
Please excuse the late reply, we are deeply sorry for not responding earlier. The amount of feedback we received in regards to the GPG Suite 2018.4 release was overwhelming. We are doing our best to catch up as fast as we can.
It seems your OpenPGP key may have expired. This KB-article explains how to extend the expiry date of your key in case it will soon expire or has already expired.