How do I reinstall the application on Facebook?
If your application is not behaving correctly, you can uninstall the application from your Facebook and re-add it. This helps resolve many common issues and your progress/activity will not be lost -- all of your progress is saved and will be accessible when you reinstall the application.
To remove the app:
1. Open the Account dropdown menu at the top right corner of Facebook and click Account Settings.
2. From the menu in the left column, select Application Settings.
3. Click Words With Friends, then click the Remove app link. Once you confirm you’d like to remove the application, it will no longer have access to your data. It will be removed from your profile (timeline), bookmarks, and your Apps and Games home page dashboards.
To reinstall the application again, visit HERE and proceed with adding the application back to your Facebook.