I have never heard of that one before.

It could be because you inadvertently set some option.

Do a factory reset:

Look in the back of your User Manual at the index.
Look for "Reset All".
Reset All will reset your camera back to factory settings.
See if that solves the problem.

If not and -->

If your camera is still under warranty with Nikon, you should call Nikon Maintenance for warranty service.

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