This error has occurred for one of the following reasons:

• You have used Back/Forward/Refresh button of your Browser.
• You have clicked twice on any options/button.
• You have kept the browser window idle for a long time.
• You have logged in form another browser window
• You are accessing the application URL from a saved or static page.
• Your have not used "Microsoft Internet Explorer" Browser

Please follow the below steps :

• We recommend you to clear your cookies and temporary internet files from your browser.
• Open a fresh browser to login again.