when "full back up" screen appears i cannot pick the "back up my data" option
I actually got it to work by disabling the screen filtering app. I had applied bluelight filter which decreases the opacity of screen. Anyhow I turned it off and the backup worked. I wasn't able to download apk's so this helped. If u have any apps that run on top of most apps or something like that as it was explained in this youtube video, I would disable them and then do what I want to do and redownload. I don't know why this is happening now because it didn't before but it helped me. Hope it helps you.