Nikon D90, FEE error?

I'm using a Nikon D90, and a 28-90mm lens.

I keep getting a FEE error below 22, how can I fix that?

Always keep the lens set to the smallest aperture (highest f-number).
Look on page 255 of your manual. The first entry (fEE error) tells you that the aperture ring is not set to the minimum aperture (highest f-number). You adjust aperture using the camera controls (the front dial on your camera), not by adjusting the aperture ring on the lens. If you want to adjust aperture, set your camera to aperture priority or manual mode and zing the front control dial.

So, set your aperture ring to the highest f-number and all will be well. If your lens has an aperture lock to keep it at the highest f-number, engage it.

The FEE error means: "HEY - PUT THE APERTURE DIAL ON THE LENS BACK TO F22".

When you want to use any Nikon in one of the auto or priority modes (anything but manual), you must put the aperture ring to the maximum aperture - usually F22.

This puts the lens into the mode whereby it can be controlled by the camera.

If you move the aperture out of this position on the lens, you must put the camera into manual mode, as that is the only mode you can manually adjust the aperture ring.

This is not unique to the D90 - it will happen on any Nikon made in the last 30 years.

Move the aperture ring to f/22.
Slide the aperture ring lock so it won't move.

Your FEE error is now history.