Lumion 12 Is Being Prevented From Contacting The License Server Site

If you are still seeing the error, go through this checklist:

If you have exhausted these options and the issue persists, you must contact Lumion Technical Support. Be sure to provide them with your System Information file (DXDiag) and the specific error message text to expedite the support process.

It’s frustrating when you’re ready to render and your software goes silent. If Lumion 12 is being blocked from reaching the license server, your workstation’s security is likely being a bit too overprotective. Here are the primary ways to fix this connection issue: 1. Whitelist Lumion in Your Firewall

Your firewall might be blocking the specific ports Lumion uses to verify your license.

Windows Defender: Go to Windows Security > Firewall & network protection > Allow an app through firewall. If you are still seeing the error, go

Add Lumion: Click Change settings, find Lumion.exe in your installation folder, and ensure both "Private" and "Public" are checked.

Third-Party Firewalls: If you use software like Norton or McAfee, manually add an exclusion for Lumion.exe. 2. Add Antivirus Exclusions

Antivirus software often flags Lumion’s background processes as suspicious.

Exclusions: Add the entire Lumion installation folder (usually in C:\Program Files\Lumion 12.0) to your antivirus exclusion list. If you have exhausted these options and the

Restore Quarantined Files: Check your Protection history for any quarantined files related to Lumion and select Restore. 3. Clean Your "Hosts" File

Sometimes, older entries in your Windows system files can block Lumion’s connection to its servers.

Search for Notepad, right-click it, and select Run as Administrator. Open the file: C:\Windows\System32\drivers\etc\hosts. Look for any lines containing the word "lumion". Delete those lines and save the file. 4. Check Your Account Registration

Starting in late 2025, Lumion required users of older versions (like 12 Pro) to have their license keys registered to a Lumion Account. If you haven't done this, the server may reject the connection. Before altering your computer settings, verify if the

Visit the Lumion Account Portal to ensure your key is registered.

Before altering your computer settings, verify if the issue is on Lumion’s end. Like all cloud-based licensing systems, Lumion’s servers undergo occasional maintenance or face temporary outages.

If you use third-party security software, you must add Lumion 12 to the "Exceptions" or "Whitelist" list within that software’s settings. Consult your antivirus documentation for how to whitelist an application.

ipconfig /flushdns
netsh winsock reset