This is the Error message that appears every time I turn on my D3100 camera since two days ago. Nothing happens if you press the shutter button one, two or 100 times. The internet has many videos about it, and they talk about a hide release button for the stuck mirror, but I really can't find it anywhere. Has anyone had the same problem before? How did you solve it? Is the expensive official Nikkon service the only way to save it?