firefox 3- Use any oldest extension or theme!

Want to use your favorite extension in Firefox but its not compatible with the new version? Or Firefox has disabled your working extension after installing a security update? Then this tutorial will definitely help you and will make your life easier.

Many times a few extensions are disabled after updating Firefox or we can’t install a new extension because its not compatible with our Firefox versions.

It happens because the developer didnt update the extension or the developer failed to code the extension compatibility version properly.

Anyway there are a few possible methods, which can be used to make any extension working in your Firefox even it was disabled because of the compatibility issue:

• Using Nightly Tester Tools extension
• Using Firefox built-in about:config tool

A. Using Nightly Tester Tools Extension:

Nightly Tester Tools is a great extension for Firefox which can help you in installing an incompatible extension or which can enable a disabled extension.

You can download it from following link:

Download Nightly Tester Tools

After installing this extension, restart your browser and after restarting goto “Tools -> Add-ons“. Now select your disabled extension, right-click on it and select “Override Compatibility” as shown in following screenshot:

It’ll confirm your action, click on “Force Install” button and you have done.

If you want to install a new incompatible extension, then just drag-n-drop the extension file into “Add-on” box and it’ll show the same confirmation box:

Click on “Force Install” button.

NOTE: After installing Nightly Tester Tools, you may notice that Firefox titlebar text is changed and a build number is also shown along with the browser name:

If it annoys you, then you can disable it by clicking on “Tools -> Nightly Tester Tools -> Options“:

Now disable “Use custom title” option or you can change it acc. to your choice.

B. Using Firefox built-in about:config Tool:

1. Type about:config in Firefox addressbar and press Enter. It’ll confirm, click on I’ll be careful, I promise! button.

2. Now right-click and select “New -> Boolean“. Give it name extensions.checkCompatibility and set its value to false.

3. Again right-click and select “New -> Boolean“. Give it name extensions.checkUpdateSecurity and set its value to false.

4. That’s it. You have done. Restart your browser and now all disabled extensions will be enabled and you’ll be able to install new incompatible extensions as well.

NOTE: You can also change value of extensions.lastAppVersion to the version no which is compatible with your favorite extension. After installing the extension, you can revert back the value. It’ll not affect the installed extension.

There is another method to hack .rdf file of the extension and change the maxversion value to make the extension compatible. But its a complicated method and is not required or recommended when we have the above mentioned easy methods.