Stuck on generating world screen

When I open the app, click on play and then select any of my saved worlds, I am stuck forever on the 'Generating world' loading screen. The progress bar only completes with green about 30-40% off the way and then disappears. 

 

I am using an iPad pro. I have restarted the device at least 40 times. I downloaded the Xbox app for ios and tried logging out and then attempting minecraft again. That did not work. This needs to be solved.