I already have it in M, and it works fine. I'm missing the diaphragm aperture ring; it's stuck and won't rotate whether I'm in the red zone or the other position. It won't move manually.In the non-red position it now rotates, but the screen shows FEE, and it doesn't fire. A mess.
If you wish to use the aperture ring on Nikon DSLRs, and avoid 'FEE', you must set the camera to use the aperture ring. It is not the default setting and that confuses many users. For some inscrutable reason, Nikon wants to dumb down the users to use the camera dials to set aperture and that requires the lens aperture to be locked. The drawback is poor handling as all functions now are done with the photographer's right hand. I always set my cameras to use the lens aperture ring if one exists. (unfortunately, this functionality is lost when F-mount Nikkors are attached to Z cameras through FTZ adapters and adds to the awkward handling of the adapted lenses. Another reason to go Z native where third-party lens makers allow true aperture ring usage).
To move the aperture ring on the lens, unlock the 'Max. aperture' lock. It is a small slider at the rear of the lens. If the camera is set up correctly, there will be no 'FEE'.
