How to Force Install Incompatible Addons in Firefox

Oftentimes you may update Firefox only to find that your favorite addon is incompatible. Since downgrading isn't a viable option, you may be at a loss for options. However, often the addon itself is actually compatible, but the version in the addon needs updating. This article will demonstrate how to override this in Firefox.Navigate to Help->About Firefox. Make note of the version number listed here, you will need it later on. In this example, it is Firefox 6 (6.0). 

1. Navigate to the Firefox preferences editor. You can do this by typing "about:config" in the address bar and hitting Enter. You will be prompted with a warning about being careful. Click "I'll be careful, I promise!".

Create a new key. To do this, right click in the body of the preferences. A menu will be displayed. Click New->Boolean. A boolean value just means one that is either true or false.

• Note: If this key already exists, you can right-click on it and click "Toggle" so that it says "false" under "Value".

4

Enter the preference name. This follows the format of "extensions.checkCompatibility" followed by the version number. In Firefox 6, for example, the preference name would be "extensions.checkCompatibility.6.0". Enter it and click OK.

5

Select 'false' in the list box to set this setting to false. This will disable the Firefox compatibility checking.

 

6. Restart Firefox for the changes to take effect.

 

Tips

• You could also use the Nightly Tester Tools extension available at https://addons.mozilla.org/en-US/firefox/addon/nightly-tester-tools/ to override compatibility checking.

Source: www.wikihow.com