I am Vineeth and I am from the Norton Support team. Sorry to hear that your browser crashes when playing Farmville with Norton Identity Safe enabled.
Can you please let me know the browser that you use? Did you receive a message that the Norton Confidential or Identity Safe plug-in has stopped responding?
Can you open the Norton product and then click Support > About and let me know the version listed there?
Please let me know the details so I can help you fix this problem.