If you find any, delete those lines, save the file, and restart Lumion. 6. The "Nuclear" Option: Clean Reinstall
If you are using a trial or a specific network license, your computer’s "hosts" file might be blocking Lumion from connecting to the server it needs to verify the installation channel. Navigate to C:\Windows\System32\drivers\etc . Open the hosts file with Notepad (as Admin). Check for any lines containing "lumion" or "act-3d." If you find any, delete those lines, save
Re-download the installer using the (do not use a third-party mirror). Reinstall with your antivirus turned OFF . If you find any
Delete the Lumion folder in C:\Program Files and the one in Documents\Lumion . delete those lines