A link may appear not work, but in fact the pop-up window is being blocked. Look for an indication at the top of the webpage or in the web address box that something is being blocked. Choose your browser below for specific information.
For Firefox browser: http://247pearsoned.custhelp.com/app/answers/detail/a_id/8966
For Chrome browser: http://247pearsoned.custhelp.com/app/answers/detail/a_id/8973
For Internet Explorer browser: http://247pearsoned.custhelp.com/app/answers/detail/a_id/8961