If you're trying to upload a file somewhere and nothing happens when you click on the "Add Files" button, you most likely need to update the version of Adobe Flash Player you have installed.  You can test to see which version of Flash Player you are using by clicking on the link below.

http://www.adobe.com/software/flash/about/

If the Adobe Flash Player software running on your computer is the latest version, please submit a support ticket online so we can troubleshoot the issue with you.