Sometimes older versions of pages are cached in your browser and can provide challenges when trying to navigate and/or log in. A good practice is to clear your cached files and cookies. Below are some instructions on how to do so in Internet Explorer 11.
Once IE 11 is open, click on "Tools" then click on "Internet Options".
From the "General" tab, click on "Delete".
From this window, make sure you just have "Temporary Internet files and website file" and "Cookies and website data" selected. After you have done that, click on "Delete".