Fatal error message: uncaught exception 102-Collection of common programming errors

I have an facebook application. In my app it’s able to pull your friends list where you can search by name or stroll down to find friend. When I type in the search box to find friend I keep getting error message Fatal error: Uncaught Exception: 102: Requires user session thrown in /home/chattabo/public_html/fbappdev/src/base_facebook.php on line 123. What does this mean and do anyone knows how to fix this?