This means your licence has expired. It may be that your button hasn't picked up the renewed expiry date after an invoice cycle.
Please right click your button and select Licensing > Refresh
This should connect to our licence servers and update your expiry date with the latest details. Your button will go back to being green if it finds a new expiry date.
This means your licence has actually expired. If you feel this is in error, please get in touch with us to find out what happened.
If you get an error saying The connection has been closed or anything indicating connection couldn't be made, it is likely that a firewall or proxy is preventing the button from connect to the licence server to update the expiry date. Please ensure the requirements outlined in our network article are met.