D800 with Non-AI Lens "ERR" Problem (Lens works with D7100 | Nikkor-P 105mm f/2.5): Nikon FX SLR (DF, D1-D5, D600-D850) Talk Forum: Digital Photography Review
How to fix Err on a Nikon camera 📷 - YouTube
Res Publica Non Dominetur – カルマン » Blog Archive » Repairing a Nikon D80 with ERR message
SOLVED: "err" message on the display, the answer is not clear - Nikon D80 - iFixit