If you are getting a Webpage has expired error like this in Internet Explorer when click the back button on a set of database results:
Webpage has expired
Most likely cause: The local copy of this webpage is out of date, and the website requires that you download it again.
What you can try: Click on the Refresh button on the toolbar to reload the page. After refreshing, you might need to navigate to the specific webpage again, or re-enter information.
Try inserting the following code in your header
header( ‘Cache-Control: private, max-age=10800, pre-check=10800’ );