If the Plug-in you're trying to install fails or isn't working, it could be for a number of reasons. Here's a list of what could be going on:

• The Plug-in may not be certified by Yahoo!. Yahoo! Customer Care can't support Plug-ins made by third parties that aren't certified by Yahoo!.
• The Plug-in may be pulling information from a source that is down or having problems at the moment.

Uninstalling and reinstalling the Plug-in that's causing the problem might do the trick. Here's how:

1. Click on the Plug-ins button with the green puzzle piece.
2. Click on the My Plug-ins tab at the top of the screen.
3. You should now see your installed Plug-ins.
4. If the Plug-in has a red stop button to the right of it, click this button now. If the button says start, do not click it.
5. Once you've stopped the Plug-in, click on the garbage can to the right of the Start button.
6. Click on the tab at the top labeled Featured Plug-ins.
7. Select the Plug-in you just deleted from the list of Plug-ins here and click on the Try it now link to the right of it.

The Plug-in should now be running in Yahoo! Messenger.

That should solve the problem.