Ionic 2 APP won't run in earlier than Android 5.0?

@fel486 I would suggest you to update your project to beta.6 which contains many bug fixes (few of them are critical). Make sure to follow the steps in the linked topic (especially steps 3 & 4) because the update is not quite trivial. It will most probably solve your problem but if it still exists after the update then paste the error’s callstack here.