1. Here's how
1.1: Please follow these instructions to add an exclusion for Lumion in Windows Defender Antivirus:
External Link: Add an exclusion to Windows Defender Antivirus
1.2: Then type 'Allow an app through Windows Firewall' in the Windows Search field and press Enter:
1.3: Click on 'Change settings':
1.4: Please click on 'Allow another app...':
1.5: In the window that appears, click on 'Browse' and select 'Lumion.exe' in the folder you installed Lumion in.
The default location is: C:\Program Files\Lumion (Version)
1.6: Click on the 'Add' button: