I have use the network license for a long time, and it works well. However yesterday, I received this message when I turn on RobotStudio: Network license not available. Premium level license unavailable (Canceled). You will still be able to use basic functionality.
Please check the expiry date. Maybe it simply expired. You can check which licenses you have installed and their expiry dates by using the tool “View Installed Licenses”:
(File → Help → Manage Licenses → View Installed Licenses)