The LightSpace CMS (and other Light Illusion software) licenses will 'fail' if any of the installed PC hardware is changed (a new disc added, or the graphics card changed for example), or the OS is changed/upgraded, and with Windows 10 this often means when a major Win 10 upgrade is automatically installed.

The license 'failure' is all part of our software protection, and can easily be reactivated by sending the license code to us via e-mail.
(Although the Win 10 'upgrades' causing the license to fain is annoying, but is a Win 10 issue, not LightSpace !))

For more information please see: http://www.lightillusion.com/upgrades_licenses.html

Steve