Summary:I keep getting "Your license for this server has expired.", but I can see from my licensing screen, that the server license has not expired yet. I received a new license file from Nintex, and I still get this issue with this one server.
Product:All Workflow for SharePoint on-premises
Make sure that the SharePoint Timer Service is running. If it isn't start it. If it is, restart it. Perform an IISRESET.