Lumion’s license verification uses secure time-stamped certificates. If your computer’s date or time is wrong (even by a few hours), the handshake will fail.

This message typically appears when you try to sign in, validate your license, or start a rendering session. The good news? It rarely means your license is invalid. Instead, it means your computer or network is blocking the conversation between Lumion and its verification servers.

If you work in a large office, the issue is likely not on your computer, but on the company network. Your IT department needs to "whitelist" the Lumion servers.

For advanced users, check the hosts file on your computer to ensure it's not blocking Lumion's connection to its license server. The hosts file can be found in C:\Windows\System32\drivers\etc\hosts on Windows. You might need to consult with IT or refer to documentation on how to edit it properly.

Follow the steps below in order to resolve the issue.

Before diving into complex settings, ensure your internet connection is stable and active.