If you are using a physical dongle, you may need to download the latest Sentinel HASP drivers separately, as the ones included in the 8.1v1 installer are often too old for Windows 10. A Note on Legal Downloads
This usually happens if your firewall is blocking the internal communication between the design app and the RIP engine. Add an exception for FlexiSign in your Windows Firewall.
One of the reasons this specific version is searched for is its versatility across Windows generations.
A functional USB port for the hardware security key (dongle). Display: 1024x768 resolution minimum. How to Install on Modern Windows (7, 8.1, 10)