So this exact thing has happened to me. I was using premiere just fine, and then decided to use apple tv. I mirrored my screen and realized premiere was small on my laptop. I then proceeeded to expand the window to the resolution of my apple tv. After I finished, I shut down apple tv, but the window was still stretched. When it returned to normal, it glitched red and disapeared. Now no matter what I do (new project, restart, shut down etc…) I can’t see any windows. When i do the apple show all Windows feature it just has the name of my project in grey. If anyone has this figured out help would be great. Thanks!