The license could not be verified: License Certificate has expired!

Symptoms

Confluence is presenting the following error message in the dashboard and/or on some pages:

Cause 

While the error appears to suggest that the Confluence license is expired, it may have actually been generated from one of ServiceRocket's add-ons that are currently installed in your Confluence instance.
For example, the Scaffolding add-on may generate this message:

But the message could also be related to a different add-on, for example, the Visibility add-on.

Resolution

Check the license status for the add-ons by going to Confluence Admin > Manage Add-ons and check for possible expired licenses.

If you have an expired license for any ServiceRocket add-on, you may renew your license by visiting the Atlassian Marketplace.

If you require help regarding your license, please contact our Support Team via our Success Portal.