Minecraft PE crashes

My Minecraft worked great for a few weeks.  Now every time i go into my world it shuts off and send me to the home screen.  I run an iPad Pro.  Tried lowering FOV under video and shutting off beautiful sky and everything that might use memory.  No change. Also tried freeing up space on my iPad.  No change.  Tried transferring my world to my iphone7 plus.  No change.  My world is only 2.5mb so don't know what the issue is.  Starting bogging down after last software upgrade but now wont run world at all.  Please help.