Minecraft PE 1.6.0 for iPad Keep getting booted. (iOS Crash)

Since the update to Minecraft PE version 1.6.0 my students keep getting booted from their built worlds.  They get into their world but after a few seconds they get booted and returned to start screen.  This is not a BETA version but through the app on the iPad. They created these worlds over the past 6 weeks. They are due to compete in an interschool competition tomorrow afternoon and cannot get in. We need a solution fast or they will be penalised before they even get to compete. HELP!!!!!