Nikon d3200 can't change f-stop?

I'm a beginner in photography and just moving up to manual mode, and I understand how to shoot in manual mode. However I'm not able to change my f-stop. I hold the button and turn the dial but nothing changes. Can someone help me here? This is all I get.

What sort of lens do you have attached to the camera? Non-CPU lenses require manually setting the f-stop with the f-stop ring on the lens.

If you look on page 193, you will see that the error you are getting is because the lens is not attached properly.

Either the contacts on the lens or camera are dirty or you have attached a lens that is NOT a Nikkor AF-S lens.

If you are using a third party lens or one of Nikon's old manual focus lenses, this could be the problem.

Since you neglected to give us all the information we need to troubleshoot your problem, we can only guess

If it's an old manual lens or a lens connected by an adaptor, then that explains it.

Your camera is only fully compatible with Nikon AF-S and AF-I lenses, or third party Nikon mount lenses.

You need to change the aperture on the aperture ring on the lens. If the lens has no aperture ring, then you can't change it. Oh, and you won't be able to use the light meter either. You'll either need to guess the exposure, or buy a light meter, or use a light meter app on your smart phone.