Please check these pages for some info on the topic:
https://ephere.com/docs/Installing_a_Floating_License_Server.html
https://ephere.com/docs/License_Server_Manager.html
Two things to check that come to mind: your firewall settings (ports 39373 and 39374 should be open) and the presence and startup status of the "Ephere License Server" in Services.
If you successfully authorized the plugin and then installed a Windows *feature* update, you'll have to release the license and re-assign it.
Ivan Kolev (Software Developer, EPHERE Inc.)
E-mail: ivan.kolev at ephere dot com
Discord: ikolev