Alt title:
Software updater fails because of error in signature verification.
http://community.rtcamp.com/t/repo-key-expired-error-for-easyengine-on-ubuntu-16-04/9227
The expiry date for the key has been extended. You can update it on existing installations using:
$ sudo apt-key adv --keyserver keyserver.ubuntu.com --recv 3050AC3CD2AE6F03Users installing EasyEngine on a fresh VPS will not have to do anything extra. The updated key will automatically be used.