i had the white screen problem & i got my game back
what you need to do is
1) Download the uninstaller for Flash Player. >>
2) Exit all browsers and other programs that use Flash
3)Run the uninstaller.
4)Verify that uninstallation is complete.
5 )Delete Flash Player files and folders.
a) Choose Start > Run.
b) Copy and paste the following and click OK. C:\Windows\system32\Macromed\Flash
c) Delete all the files in this folder
d) Choose Start > Run.
e) Copy and paste the following and click OK.C:\Windows\SysWOW64\Macromed\Flash
%appdata%\Adobe\Flash Player
%appdata%\Macromedia\Flash Player
f) Delete all the files in this folder
6 ) Restart Your Computer
7 ) Download & install the latest Flash Player from >>
Now Just Open Farmville & Play
) 
