Hello friends. Don’t mean to just puke all over everything, but in my situation, it is hard not to. 
Back when I had Cubase Elements with the “soft” Elicenser, there was a recurring problem where (seemingly rhandomly, every once in a while) I would go to bring up Cubase and a message would pop up saying that my license wasn’t valid. I would re-install it and sure enough, the same thing would happen again a few weeks later. Talked with Steinberg tech support, and they said that it could be the Windows security software that is causing the problem. I was already about to upgrade to Artist, and they thought that using the hard Elicenser would eliminate my issues. Well, I recently upgraded to Cubase Artist, and…yeah. I click on Cubase, click on my project, and as everything is loading, a message pops up saying my license is not valid. It seemed to be triggered by a new reverb I noticed that I had clicked on earlier, where the same bubble popped up, telling me I couldn’t use it. Whether I click “retry” or just “cancel”, all it does is lock up the screen to where all I can do is to restart the computer and go through the cycle again, only to find the same thing happening. Let me add that this computer is a brand spanking new laptop with Windows 10. Cubase is the only app I have installed on it. You claim that it works with Windows. If it is the Wndows security system that is causing problems, I believe it is on your shoulders, Steinberg, to resolve this. Many thanks to the helpful bunch that you guys are. I appreciate any insight that may help solve this problem.