So I recently got my galaxy s4, it is also not rooted and whenever I change the lockscreen wallpaper it just switches to a kid running with balloons. The only way I can get it to actually work is if I switch it to a default wallpaper and then switch it to the one I want. I'd really prefer not to have to do that every time. This is my first post so if I did anything wrong, sorry. But thank you for any help.