If you have recently updated to Windows 8 and are having problems loading your Farm, try this link: http://helpx.adobe.com/flash-player/kb/flash-player-issues-windows-8.html
Don't forget that the game can sometimes get confused when you're signing in and out of different Facebook accounts in the same browser. The first step we recommend if you're having loading troubles is to clear your cache and cookies.
For more information: http://www.facebook.com/help/?page=185360664848864
Thanks for playing!