1.Open firefox and click on the "Tools" button at the top of the screen.(if you dont see this button, press the alt key on your keyboard to make it visible).
2.Under "Tools", click on "Add ons".
3.The "Add ons" manager should now open. Here, click on plugins.
4.Check if you see "Shockwave Flash" listed. It should also contain the version number.
5.Verify that the Shockwave Flash plugin is enabled. (If you see a disable button to the right side, that means it is enabled. If you instead see an "enable" button, click on it.
Verify if Firefox recognizes flash after you perform the above steps. If you do not see "Shockwave Flash" listed, please try uninstalling Flash Player from the control panel and reinstall from the link provided below:
Once you click on the above link, choose the relevant operating system and browser and then click on the "Download" button.
The Flash player on Google is embedded. On Firefox, it's a plugin. To install it on Firefox, close the browser first.