1.6.2 P.E i.o.s only opens one world at a time

When I open Minecraft after I have refreshed the app, I can open any world. But if I leave that world, I can’t open another world again until I exit out of Minecraft and go back in. When I try clicking on the image, it puts me in a screen that says “Updating one of one packs”, and then it puts that world to the top of the list of worlds, but it doesn’t go into that world. Also, I don’t use any packs. See the screenshot below. I also have deleted the packs that I use all together, and it doesn’t work.