If you have tried all the steps above and the error remains, visit the official Lumion Technical Support forum. Provide them with a screenshot of your hosts file and your firewall outbound rules. Usually, a fresh uninstall using a tool like Revo Uninstaller (to scrub the registry) followed by a reinstall is the final nuclear option.
Introduction: The Frustration of a Blocked License If you have tried all the steps above
If these three fail, proceed to the surgical fixes below. Step 1: The Windows Hosts File (The #1 Culprit) This file is the final authority for domain name resolution before DNS. If it contains a redirect for Lumion’s server, nothing else you do will work. Introduction: The Frustration of a Blocked License If
You have just double-clicked the Lumion 12 icon. Your project deadline is looming, and you need to render a high-resolution walkthrough. Instead of the familiar splash screen, you are met with a red alert: "Lumion 12 is being prevented from contacting the license server." You have just double-clicked the Lumion 12 icon
By methodically working through this guide—cleaning the Hosts file (Step 1), creating Firewall rules (Step 2), adjusting Antivirus (Step 3), and checking your proxy (Step 4)—you will restore your connection within 10 minutes.