Nikon F100 not focusing
Hi everyone, I'm new to analog photography and have been using my Nikon F100 with a Nikon AF 24-120mm f3.5-5.6 D lens for a few weeks and experienced a new problem today after loading a new roll of film. The problem is that I can't get the camera to focus on anything in focus mode S, so I'm unable to take any photos. The lens just keeps going from the min to max value and won't actually lock in on anything. When in manual mode I can click the shutter button and the film counter advances, but the display says "Err." The batteries are showing as full but I still removed them and put them in again, I've turned the camera on and off again, read the manual and verified that the AF settings are still the defaults, taken the lens off and put it back on again, cleaned the electronic lens contacts, and I'm at a loss for what else to do. I was using this film just a couple days ago with no problem and haven't intentionally changed anything. Any advice would be super appreciated.