I use a Nikon D7000. I've been practicing Manual mode. Everything was fine until today. For some reason the meter won't move. It's stuck to the right of the "0" along the meter. I reset with the green buttons, switched lenses. Nothing works. Is it a setting that I locked it into? I've watched videos and researched it but can't figure out why it won't move.
I have a D7000 as well and experienced the same issue back when I first got it. In my case, having Auto ISO enabled was the culprit, and disabling that solved my problem immediately.
Otherwise, I'm confident a factory reset would also clear out the problem.