
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 version. It happens because the developer didn't 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 Firefox even if it was disabled because of the compatibility issues:
- Using Nightly Tester Tools extension
- Using Firefox built-in about:config tool
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:
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.
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.
IMPORTANT: In Mozilla Firefox 3.6 and later, the above mentioned method no longer works. Actually the "extensions.checkCompatibility" preference has been replaced by a new preference "extensions.checkCompatibility.<version>" that also includes the application version number.
Here "<version>" represents alpha and beta build numbers. Its value is given by the first few characters of Firefox version matching the following pattern: <number>.<number><letter>.
For example:
For Firefox 3.6 -> extensions.checkCompatibility.3.6
For Firefox 3.7a1 -> extensions.checkCompatibility.3.7a
For Firefox 3.7a2 -> extensions.checkCompatibility.3.7a
For Firefox 3.7b1 -> extensions.checkCompatibility.3.7b
For Firefox 3.7b2 -> extensions.checkCompatibility.3.7b
and so on...
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.
BONUS TIP: 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.
Complete list of AskVG articlesThis article was posted in Browsers, Mozilla Firefox, Troubleshooting.
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Omi Azad
Uhu,
Could not install Google Toolbar on my Minefield.
VG
^^ Google toolbar is not compatible with minefield atm. They'll release a compatible version very soon.
But you can try following extensions which can fulfill your requirements:
https://addons.mozilla.org/en-US/firefox/addon/33
https://addons.mozilla.org/en-US/firefox/search?q=google+toolbar&cat=all
Anmol
i couldn't install mcafee site advisor
khalid4ever
nice tutorial Vishal

excuse me VG may i know the name of the theme u r using on Firefox !!
i like so much
best regards
Omi Azad
@khalid4ever
I think it's simple FF3 on Vista. If you are on Vista, you will see windows like that.
khalid4ever
^^ tnx Omi for reply
i'm running XP :'(
wish i have a theme liken this on XP
VG
Hi Khalid
Omi is right. Its Windows vista and the theme which I'm using is "AeroVG".
Sora
Hi Vishal,
I tried this to enable crawler toolbar on firefox 3 but it made firefox 3 unable to start, i had to disable it in the safe mode but is there anyway to make it compatible with firefox?
VG
^^ It means its not compatible with Firefox 3.0 and you can't do anything except waiting for an update from the extension developer.
Piyush