The following things may help.
- Clear cache and cookies of your computer. How to do this, is described on this page: https://www.facebook.com/help/?page=185360664848864
- Change your browser.
- Check your internet connection.
- Reset your router.
- Make sure you have the most recent version of your browser and Flash Player.
- Use a different computer if possible.
- Close all uploads, downloads or programs other than the ones used to play the game.
- Don’t use the scene called “Snowing”.
- Don’t make your farm too big.