Error: Failed to connect to server due to Network Error

From the announcement,

This release of LightBurn includes support for EzCad2 based galvo controllers, more commonly referred to as “fiber lasers”. It supports both fiber and CO2 laser sources driven by an EzCad2 supported control card, using USB to connect to your PC, Mac, or Linux system. UV laser support will be added soon, along with support for BSL (SeaCad) based galvo systems.

And this is worth review for greater understanding of ‘How the License Works’,