Even though the portal is browser-based, it relies heavily on its own navigation tools instead of those built into your web browser. Because of this, the Back and Refresh buttons in your browser will sometimes generate errors when used.
To avoid this, please be sure to use links within the portal itself to navigate. Each page has breadcrumb links (prefaced with "You are here:") underneath the blue main menu that will aid in this.
Links in the blue main menu are referred to as "tabs." Links denoted by a folder icon in the menus on the left hand side of the page are referred to as "sub-sections." Links in the same menus on the left hand side of the page that do not have folder icons are referred to as "pages."