Before fixing the problem, you need to understand the "why." Lumion 12 uses a continuous online validation system (often called "phone home" licensing). Unlike older software that used static license files, Lumion 12 must periodically ping its license server to confirm your subscription is active.
To resolve the "Lumion 12 is being prevented from contacting the license server" error, follow these step-by-step troubleshooting guides: