FEE error with AF 50mm on D7000

Just upgraded from D70s to D7000 last week bought brand new from authorized dealer. When I attached my fav lens AF 50mm 1.8, FEE error displayed on top LCD despite rotating the aperture ring to smallest aperture of f22 and locking it. With my old and trusty D70s it's working perfectly and did not have this same error ever since. Tried to put the said lens on a friend's D90 and also worked well. Not even once error message Tried to clean contacts but still same error message appears when i switched on the camera. Did anybody have this experience on D7000? All my other nikkor lenses worked wonderfully with D7000

The locking mechanism has zip to do with it. It's a mechanical interlock that merely prevents one from accidently turning the aperture ring away from minimum aperture. Whether it's locked or not, the camera cannot detect that and thus does not care.

Past that, I was going to suggest cleaning the contacts, but I see you've already done that. Do you have any other pre-G lenses you can try? If they all have that issue, the problem is the camera. If it's just that one, it's the lens.

Just to update, i found a way to go around the FEE error when i mount my nikkor AF 50mm 1.8 on my D7k. On the CUSTOM SETTING MENU, f Controls, f6 customize command dials, go to Aperture setting and select Aperture ring, select Ok. With this setting, no need to set aperture ring at the smallest aperture f22 and locking it. Instead of using the sub-command dial to change aperture, i rotate the aperture ring manually to change aperture.
I loved this feature of the D7k as it will accept older lenses with aperture rings(pre G lenses)