If you have already installed Firefox 5(Aurora/Beta/Final) probably some of your plugins are already not working. Plugins will get disabled by itself and even you wont be able to install any new incompatible plugins.
![](https://classictutorials.com/media/posts/168/Not_Working-thumb.png)
![](https://classictutorials.com/media/posts/168/Working-thumb.png)
If you have already installed Firefox 5(Aurora/Beta/Final) probably some of your plugins are already not working. Plugins will get disabled by itself and even you wont be able to install any new incompatible plugins.