I have a canon 5D Mark Iv. I got an error 01: “Communication between lens and camera is faulty” with my 24-70 mm lens. I read to carefully clean the gold contacts with a lens cloth. I did and tried it again and got the same error. I tried a different...
Thank you for the response. The 24-70 mm lens had the Err 01. When I tried a different lens, it connected okay, but my camera wouldn’t focus at all on live viewing with any of my lenses.