Hi, I have a D750 (with grip) that is about 5 months old. Today, turning on the camera, and a 105mm F2 D DC lens attached (which I used the day before without issue and I did not remove it since), I see an FEE error. The LCD says the memory card may be damaged, so I tried swapping out each of the 3 cards I have, and get the same error. I disconnected the grip, whose battery was at 50%, so I have the camera battery in the 90% range. I checked the 105mm and made sure the aperture is at f16 and the lock switch is on, and I see the same error. Tried switching the lock on and off several times, and taking the aperature setting off f16 several times as well. Same issue. Tried dismounting and remounting the lens a few times, and wiping off the ring and contacts on the lens and body with a cloth. I put on my 50mm G lens, and it works fine. I put on my 28mm F2.8 Ais lens and set the non-CPU setting to that lens, which is manual aperture. The camera doesn't show an FEE error, but the display shows as f4.5, regardless of the setting on the lens. I put on the 85mm f1.8D lens I have, which is locked at minimum aperture, and it shows a FEE error too. Seems like an issue with the body. Any ideas? Firmware? Anything I can clean or check?