you can try closing the browser and reopening it,  when the screen is blank you try dragging the bar to the left rightwards using the mouse, or maybe java is not running so you can check on th bottom right arrow for, click on it and check if java is running, if java is not running  restart your computer. but if java is running  go to the url bar and click the down arrow on the right wich shows recently used addresses and  select the one written nflsageserver2/AUTHORITY and use that one.