Black screen/Frozen screen

When trying to use the build Ar, the screen wi sometimes freeze, and stay that way, forcing you to close the app and attempt again.

 

When a tappable is done and you are about to go back to the map. The screen  will sometimes go black,  this can also happen when first click on a tappable, going into a different  menu, or using the build Ar. You can hear the cluck of chickens in the background, laughing at you. So the game is running but you just cannot see anything.