Flash Videos showing as a black box in Firefox

Problem

When viewing Flash videos on Youtube or other sites within Firefox, the video will either come up as a black box with no sound or just play the sound, this issue can be present on some videos and not others.

Cause

The Flash plug-in for Firefox has become corrupt.

Solution

1. Try and disable the plug in and then enable it after a restart. You can do this by following these steps:
   1. At the top of the Firefox window, click on the Tools menu, and select Add-ons on the menu bar.
   2. Click on the Tools menu, and select Plug-ins.
   3. Click the button next to Flash plug-in to disable and then restart Firefox.
   4. Re-enable the plug-in again and restart the browser.
2.  If this doesn’t work  try uninstalling Firefox and Flash from the machine by:
   1. Click on the Start button then Control Panel.
   2. Go to Programs, and then clicking Programs and Features.
   3. Select a program, and then click Uninstall on Flash and Firefox.
   4. Restart the computer, then download and install the 2 programs from these pages:
      • http://www.mozilla.org/en-US/firefox/new/
      • http://get.adobe.com/flashplayer/