For detailed information and a thorough clearing of Cache content, click on the above link
For a simple clearing of your browser:
STEP 1: Place your mouse cursor in the https address bar, click to highlight the current URL address, and hit Enter. This refreshes your browser.
STEP 2: The issue may be with the browser itself such as with Chrome, so then try Explorer or some other browser with which you are familiar.
STEP 3: If a video does not play, and you don't want to download a different web browser, you can choose to update the Flash Player plugin for your current browser. Use this link to install the update: http://get.adobe.com/flashplayer/ After the installation is complete, return to the page to see if it is working now.