Version 1.12.0 of minecraft for iPad opened fine and this morning I updated to v1.13.0 of iOS minecrat for iPad. When you start minecraft it shows the white loading screen, then it suddenly returns to the home screen. If I double tap the home button, I see that I can switch to minecraft and the thumbnail shows its at the main menu. However when I try to switch to minecraft it immediately returns to the home screen again.

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https://minecraft-el.gamepedia.com/Pocket_Edition_hardware_performance_(iOS)