Hello, I keep getting a popup saying "Sentinel LDK Protection System: Feature Expired". When I click OK the message pops up again and the only way I can get rid of it is to restart. I've searched for 'Sentinel' on my finder and I have no files with this name, and the popup just keeps coming up. Does anyone know why this is happening or how I can get rid of it? I have a MacBook Air. Thanks!