Causes of Elemrnt is undefined in session

[Guest]

Every once in a while on a Coldfusion a page I now maintain, the following email message occurs "Element UTIL.PAGE is undefined in SESSION." The variable session.util.page is defined in the login process of a user and subsequently updated by the application. What are any other causes of this error besides the session variable not being defined?

[jazz823]

your session may be timing out. You could have the link to the page has a resolved URL which can reset the session. Those are 2 possibilites