Just ran into a pretty nasty bug for the first time. Navigating to any picture in Photos and hitting the "share" button expands the picture to fill the window; no share sheet shows up. This happens with every picture, and does not seem to be fixed with multiple resets. After the photo fills the screen, it becomes unresponsive to touch - you cannot invoke Control Center, Notification Center, the app switcher, or utilize the power button independently. This is bad. Hopefully killing RAM will fix things, but I'm reporting regardless.