I'm not sure what the error is - since I can shut my Twine 2.13 program off through Task Manager, and hitting the "X" key in the app when it's opened. I've also got Windows 10 and I think the Creator Update added to it.
So, I couldn't tell you why you're having this issue. Maybe if you explain how you installed it? You could always just try to reinstall it? If that fails, maybe someone else here can help more.