Open (Right-click Start > Terminal (Admin)).
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.
: Verify the license key is registered in your License Keys overview before restarting the software. 2. Check the Windows Hosts File Open (Right-click Start > Terminal (Admin))
Before diving into the fixes, it helps to understand why Lumion 12 suddenly loses access to its server. The software relies on specific ports and addresses to communicate with backup.lumion3d.net and license.lumion3d.net . If this path is broken, Lumion defaults to a secure, locked state. The most common culprits include:
Have a tip of your own? Share it in the comments below or tag us on social media. Happy rendering! Usually, a fresh uninstall using a tool like
: Click on Allow an app or feature through Windows Defender Firewall on the left-hand panel.
: Turn off the antivirus shields for 10 minutes to test if Lumion launches successfully without it. 4. Reset Local Network and DNS Cache Check the Windows Hosts File Before diving into
Under , click on Protection history . Look for recently blocked items associated with Lumion 12. Click the item actions and select Restore .
Corrupted system files can prevent Lumion from starting the license verification process.
How to Fix "Lumion 12 is being prevented from contacting the license server"
Open (Right-click Start > Terminal (Admin)).
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.
: Verify the license key is registered in your License Keys overview before restarting the software. 2. Check the Windows Hosts File
Before diving into the fixes, it helps to understand why Lumion 12 suddenly loses access to its server. The software relies on specific ports and addresses to communicate with backup.lumion3d.net and license.lumion3d.net . If this path is broken, Lumion defaults to a secure, locked state. The most common culprits include:
Have a tip of your own? Share it in the comments below or tag us on social media. Happy rendering!
: Click on Allow an app or feature through Windows Defender Firewall on the left-hand panel.
: Turn off the antivirus shields for 10 minutes to test if Lumion launches successfully without it. 4. Reset Local Network and DNS Cache
Under , click on Protection history . Look for recently blocked items associated with Lumion 12. Click the item actions and select Restore .
Corrupted system files can prevent Lumion from starting the license verification process.
How to Fix "Lumion 12 is being prevented from contacting the license server"