Step 1: Close Outlook and other MS office Applications
Step 2: Start menu -> Google Apps Sync -> Delete saved google apps sync passwords
Step 3: Now open your Outlook with Google Sync profile “Google Apps – email@example.com”
Step 4: This should prompt you one pop-up box, enter your email address “firstname.lastname@example.org” and press “Continue”
Step 5: This should open your default browser and will prompt you to login with your Google Apps account.
Step 6: After successful login, select “Allow” button to reassign the Auth to your Google Apps sync tool for Outlook.