Got an old extension that quit when Mozilla got deep into the 3.0 series? Make it work again with a couple of mouse clicks.
I have a lot of extension installed in my Firefox 3.5 called RSS Editor, which quit working after the first update of Firefox 3. It was compatible up until then.
That mean I could use it at all, even though there’s no problem with its functionality or compatibility. And, sadly, the guy who developed it hasn’t kept it updated to keep up with FireFox changes.
Then I found this tip on the Web, and it will work for you.
You can also make all your favorite but outdated extension compatible with Firefox 3.5 again (even from FireFox 2). Just dowhnload and install Nightly Tester Tools: https://addons.mozilla.org/en-US/firefox/addon/6543 and “override all compatibility” in the extensions window.