If you are enabling an add-on or installing/changing the theme in your firefox the effect will be seen only after the Firefox is restarted make you wish if there was a Restart Button like you get when you Install a Add-on.
And if you were working on many tabs, invariably you loose all the tab information and because you can’t restore a session if you accept to close tabs
Here is a simple solution that make you wonder why didn’t the Firefox think of this ?
A simple Firefox add-on called Restarter ! Now if you need to change a theme on your Firefox or need to enable or disable a firefox add-on / extention all you need to do is Click on Restart Firefox from File Menu.
You will be prompted to agree to close the open tabs, All you tabs will be restored once firefox restarted.