Hi,
It seems like your license is not attached to your domain.
You haven't updated your Acymailing for over a year. I'm not sure in which version the license tab was added. Please go to Acymailing->Configuration and check if the license tab is present.
If present, unlink your license, save your config and then link your license again.
When this does not resolve your issue or in case you do not have a license tab in your Configuration, please raise a support ticket here: https://www.acymailing.com/support.
