This is likely caused by a user error. The FEE error indicates that the camera cannot control the full range of the lens's aperture. This occurs with lenses that have aperture control rings. You probably didn't set the aperture control ring of the lens to its smallest setting when you mounted it on the Df camera, but did do so when it was mounted on the D3300.

Lens apertures are spring-loaded to default to the smallest aperture (i.e., highest f-number). When the lens is attached to the Nikon camera, the camera's aperture control lever opens the aperture to the lens's widest possible opening. This is to allow the most amount of light into the viewfinder for focusing and autoexposure to work best. When the shutter is triggered, the camera's aperture control pin allows the lens aperture to reduce to the aperture value set in the camera (either automatically in the Program or shutter-priority exposure modes, or manually by the user in the manual or aperture-priority exposure modes).

For lenses that have aperture control rings, if the aperture control ring is set to anything wider than the smallest aperture, then the camera has no ability to let the aperture spring in the lens close the aperture below what the ring is set to.

For instance, the Tokina AT-X M100 AF Pro D 100mm ƒ/2.8 Macro lens (the only macro lens made by Tokina) has a minimum aperture of ƒ/32. If the aperture ring were set to, say, ƒ/11, the camera cannot set the aperture smaller than ƒ/11, because once the camera's aperture linkage lever moves past the ƒ/11 position, the lens's aperture control ring stops the aperture from closing any further.

This is what the fEE error is telling you. To resolve the problem, set the aperture of the Tokina lens to ƒ/32. Incidentally, this is why the 32 on the lens's aperture control ring is green, to indicate it is a special setting. The lens also has an aperture lock switch, to prevent you from accidentally changing the aperture control ring.

• The lens's product page says:

  When set on other than the minimum aperture value (F32), the "FEE" error message flashes and the shutter cannot be released.

• Nikon's support article, What does the FEE or F-- error message displayed on an SLR camera mean?, says:

  The FEE error indicates that the camera cannot control the full range of the lens aperture. If your lens has a mechanical aperture ring, rotate the aperture to its smallest opening, or highest f-number - normally marked in orange. Select this aperture and lock it using the aperture locking switch to prevent this message from appearing again.