Resolving Page Expired Error Message in PubMed®

July 22, 2005 [posted]

NCBI is using HTTP1.1 compression/content encoding with Entrez databases (e.g., PubMed). Data compression allows data to be sent faster - a big help for users who have slower connections.

Most recent versions of popular browsers are by default enabled to use HTTP1.1. If, however, users see the message, "Warning: Page has Expired," after using the back button in their browser, they should enable HTTP1.1 compression in their browser. The steps to enable HTTP1.1 compression in Microsoft® Internet Explorer (MSIE) are:

From the Tools menu, select Internet Options.

  • Click the Advanced Tab.
  • Scroll down to HTTP1.1 settings.
  • Check the following checkboxes: Use HTTP1.1 and Use HTTP1.1 via proxy connections.
  • Click OK.
  • Close MSIE and re-open it.

If, after enabling HTTP1.1 compression (be sure to close and re-launch the browser), users still see the "Warning: Page has Expired" message, it is possible that another application is responsible. For example, we have determined that, even with HTTP1.1 compression enabled, Symantec's firewall program, Norton Internet Security™ can cause the browser to display the error message if the firewall is configured to monitor HTTP connections, which is the default configuration.

If, in the case of a firewall program, users wish to disable HTTP monitoring, they should fully understand the consequences of doing so.