Original post by: George A. ,
Have you restarted your tablet? If not, hold down the power button until the screen turns black or until it says "powering off." Also, make sure your auto-rotate is on. Pull down to get to the quick settings (above the notifications) and tap the button that has the tablet orientation on it. If neither worked, a factory reset should. A factory reset will restore the tablet to the way it was when it came from the factory, and delete everything including photos. Move any important data to a PC. Then, go to settings, backup & reset, and then factory reset. Hope this helps!