Purchased worlds fail to open

So, i had spent $15.00 on the minecraft store recently. I bought Pixelhead's Pet shop world, the Dragons world by InPvP, and the woodsville map by Shapescape.

 

But no matter what i did, they don't load. I tap them, and it doesnt even load. it just says "this world cannot load". My normal default world and any new worlds i made were fine, but using the templates didnt work.

 

 

thankfully, at the time of writing this, i managed to get my pet world to work, but i dont know for how long. I don't know what caused it, but i hope it doesnt happen again. it only started this after the summer sale started.