The paths established during the "Sentinel" driver installation or the registry registration might have been moved or deleted.
If you had a VPN active when you installed it, turn the VPN on.
executable are set to "Run as Administrator" via the right-click menu. Verify Hardware ID (UID) : Most installations require generating a Unique ID (UID)
Major Windows updates can change how the OS reports hardware IDs to the software.
Manually editing the Windows Registry to reset the license timers or clear old HWID data.
If you are using a "Sentinel" emulator, go to the folder where the emulator is located.