When it says Storage is full and it needs to progress

When I was playing Minecraft It said storage was full it could not save progress I don’t this is a bug this has to fixed After that I tryed to join my world it will not let open my world 

better if’s it was progress in the background and it will not let me join my friends server 

I am on iPad Pro

if you need to know my device 

Minecraft Bedrock Editon for iOS