Lumion 12 Is Being Prevented From Contacting | The License Server

Troubleshooting Guide: "Lumion 12 is Being Prevented from Contacting the License Server"

Date: April 21, 2026
Category: Troubleshooting / Technical Support
Reading Time: 4 minutes

"Lumion 12 is being prevented from contacting the license server. Please check your firewall and internet connection." Troubleshooting Guide: "Lumion 12 is Being Prevented from

Click Change Settings, then Allow another app, and browse to your Lumion.exe. Add Antivirus Exclusions: If you haven't done this, the server may

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. Look for any lines containing the word "lumion"

Search for Notepad in your Start menu, right-click it, and select Run as Administrator. Open the file at: C:\Windows\System32\drivers\etc\hosts. Look for any lines containing the word "lumion". Delete those lines, save the file, and restart Lumion. 4. Verify Administrative Rights