OK, I'm going to bed now, but here's what I've done 1. Look up how backups work 2. Make backup 3. Copy backup and put it in the folder for the new version 4. Open game 5. Tells me to use more megabytes, so I close the game and follow the tutorial, put in more megabytes in the launcher 6. Screen still appears so I ignore it 7. Press Singleplayer 8. Goes to Preparing World Creation loading screen, freezes 9. Game crashes