That will happen if you've been running your game for very long prior to a crash. The game is saved only when you exit to the launcher or another app, so when you launch Village Sim again after a crash, you will revert to your previous save game (and things are usually drastically different as a result). It's more important to report the exact kind of crash you had - since that's the real bug, and Arthur can only fix it if he knows what kind of crash you had.