Check the field. If it states "Perpetual" or does not list an expiration date for the base software , it is a fixed license.
Open Zemax License Manager. Check the "View License" tab. If blank, your softkey may have become unhosted due to a Windows update. Re-enter your activation key.
| Feature | Specification | |---------|----------------| | | Hardware ID (HDD serial, MAC address, motherboard UUID – combined hash) | | Activation | One-time online/offline (via .xml response file) | | Deactivation | Manual release via Zemax License Manager (ZLM) – limited count per year | | Persistence | Survives OS updates; fails if core HW component changes | | Network requirement | Only at activation/deactivation; zero runtime network calls | | License server | None – runs entirely on local host |
Unlike modern software that requires periodic online check-ins (every 30, 90, or 180 days), older versions of Zemax OpticStudio with a classic perpetual fixed license (pre-2023 subscription push) can run forever on a dedicated, air-gapped computer. No phone-home, no license server dependency, no expiring tokens.
: This is the "fixed license" model. It grants you the right to use a specific version of OpticStudio indefinitely, without any recurring fees.