Lumion.exe within that installation folder.
If you use a third-party firewall, ensure it allows traffic via Port 80 (HTTP) Port 443 (HTTPS) for Lumion-related domains. 3. Clean Your "Hosts" File Lumion
This article provides a deep dive into why this error occurs in Lumion 12 and offers a step-by-step, technical walkthrough to resolve it permanently. Lumion
: Add an exclusion for Lumion.exe in your Windows Defender Firewall . Lumion