Heyy, I wanted to upload a new banner because I changed my channel name. But Youtube said that I need to use a PNG, JPG or GIF file. So I tried different pictures that worked before and I even downloaded a random picture from google and they all refused to work. Youtube keeps saying the same. Then I tried it on my other channel with the banner that was for my main channel and it worked the first time I tried. I used different browsers, logged out and logged in, deleted my history and cookies but it still doesn't work. Does anyone know what else I can do and what's wrong? Thanks!