Hi folks. I received a lens error first on my Canon 17-55 and then later on my Canon 28-135. It states "Err 01 Communications between the camera and lens is faulty. Clean the lens contacts. My understanding is that this is a pretty common error that lots of folks have received. I Googled how to resolve it and found that most of the advice was to clean the contacts on the lens itself. I have done that with a soft cloth as I was shown in several Youtube Videos. I even cleaned the actual camera contacts the same way. The lens will work for several shots then I get the error again. One thing that may or may not be a factor, it seemed to occur again when I dialed down to F8 from a larger aperture. It's quite frustrating as I'm not in a position to buy new lenses. Another video I saw on Youtube said to take several pictures with the lens off the camera. I have not done that because that just sounded strange to me. I hate to have to send these lenses into Canon and spend $200+ to have them "repaired" but not sure what else to do. Any other suggestions? Both lenses are several years old. They were used initially on a Canon 40D and then later (and currently) on a Canon 7DMarkII. Thanks in advance!