To fix this problem, you have to prevent Firefox from checking its version number before it tries to load extensions.
You can do this by adding a new preference value.
1. Point your firefox browser at the URL to “about:config“.
2. Right-click on the preferences list to bring up the contextual menu. You should see an option that says “New.” Select that, and choose “Boolean.”
3. When it asks you for the preference name, type “extensions.checkCompatibility” (without the quotes). You have to enter the name exactly. For the value, choose “false.”
4. Restart Firefox. Firefox should give you a warning that version checking is disabled. You can double-check under “Tools:Add-Ons” to make sure everything is activated once again.
Just in case anything bad happens, there’s always a backup plan. Just tell Firefox to “Reset Prefrences”, restart and you will have extension compatibility turned back on again.
This helped a lot especially in getting some of the extensions that I’m using in firefox to work again since I’ve updated to Firefox 3 RC1 Firefox 3.
Edrei says
You know…there is an easier way at this. Just install the Nightly Tester Tools add-on for Firefox and hit the button that says override all compatibility.
And that’s it. No messing around the about:config.
David says
Thanks for the tips, Edrei.
Schnouki says
This works with Firefox 3.1 beta 2 too. Thanks! 🙂