How to Fix Broken Incompatible Extensions in Mozilla Firefox and Make Them Compatible With Newer Versions?

So you installed a new version of Firefox or installed an update and now your favorite extension is no longer working. It has been disabled by Firefox. Do you want to re-enable your favorite extension or want to install an incompatible extension in Firefox?

Don't worry! You have come to the right place. This tutorial will help you in making your favorite extensions compatible with Mozilla Firefox and will also help you in installing incompatible extensions.

Many times a few already installed extensions are automatically disabled after updating Firefox version or you can't install a new extension because its not compatible with 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 Add-on Compatibility Reporter extension
  • Using Firefox built-in about:config tool

A. Using Nightly Tester Tools Extension:

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


You can download it from following link:

Download Nightly Tester Tools

It also provides many other useful features like:

  • Customize Firefox titlebar text
  • Copy build tag to clipboard
  • Copy list of installed extensions to clipboard
  • Open profile folder
  • Take screenshot

B. Using Add-on Compatibility Reporter Extension:

Add-on Compatibility Reporter is an official Mozilla Firefox extension developed by Mozilla itself which automatically enables incompatible extensions and let you report them to Mozilla.

This extension allows you to test whether your favorite extensions still work with the version of Firefox that you're using. If you notice that one of your add-ons doesn't seem to be working the same way it did in previous versions of the application, just open the Add-ons Manager and click Compatibility next to that add-on to send a report to Mozilla.


You can download and install it using following link:

Download Add-on Compatibility Reporter

Thanks to our readers "Archy" and "carbonize" for mentioning it...

C. 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". Set its name in following format:


For example, if you are using Firefox 10.0, you'll need to set the name to extensions.checkCompatibility.10.0 and if you are using Firefox 11.0 beta, you'll need to set the name to extensions.checkCompatibility.11.0b. Similarly if you are using Firefox 12.0 alpha, you'll need to set the name to extensions.checkCompatibility.12.0a and so on.

Now set value of this new boolean key 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.

BONUS TIP: There is another method to modify .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.

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Posted in: Mozilla Firefox, Troubleshooting

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  • I unable to install google toolbar..can anyone provide me the setup file ?

  • VG

    ^^ Google toolbar has been discontinued for Mozilla Firefox:

  • This option is no longer available in the latest version

  • right click on what!!

  • VG

    ^^ Right-click anywhere in the list.

  • those methods you call "easy"?
    to hack the install.rdf is easy.

    1. download *.xpi you require
    2. rename it to *.zip
    3. extract install.rdf (by total commander it is one key operation)
    4. open install.rdf with a text editor (notepad is good enough, dont use Word)
    5. find and change value as needed, e.g. 27.0.*
    6. if you have the extension already installed, you have to change
    as well, otherwise firefox rejects to install, as it already has that version... (e.g. 0.9.7 -> 0.9.7b)
    7. copy the modified install.rdf back to the *.zip (total commander again, or repack)
    8. rename the *.zip back to *.xpi
    9. install and enjoy

  • ...
    5. find <em:maxVersion> and change value as needed, e.g. 27.0.*
    6. if you have the extension already installed, you have to change <em:version> as well, otherwise firefox rejects to install, as it already has that version... (e.g. 0.9.7 -> 0.9.7b)

  • @ MaBe,

    Can you modify IDM Add-on .xpi to work with the Firefox 31.0a1, I don't want to install Total Commander, and when I tried to rename/unzip and repack it gave me a error message saying the file is corrupted.

  • @TheAslan
    check this out, latest IDM CC:

  • I did it, here's what I did:

    1. Download .xpi file and rename it to .zip
    2. Do not extract .zip archive, but double click it
    3. Double click install.rdf file and open it in Notepad
    4. Modify to match your browser version
    5. Choose Save as and select all files so it saves it as install.rdf and not install.rdf.txt
    6. Now double click .zip archive again, but now remove META-INF folder
    7. Drag and drop install.rdf file top of the .zip file
    8. Select replace
    9. Rename .zip back to .xpi
    10. Install Add-on

    You should AskVG also mention this META-INF folder, so users knows they have to remove it to make modified .xpi files work again.

  • I was looking through my extensions and noted that some of them were marked false. does this mean it is not working? I also have a this browser.newtab.url which opens this url every time I open a new tab.

    How do I fix this. I am worried that my security is compromised.

  • VG

    ^^ I'll advise you to completely uninstall Firefox from your system with the help of following tutorial:

    Also run CCleaner after uninstalling Firefox:

    It should help.

  • I have tried all the methods but the theme Macosx For firefox is still not installing .
    When I dreg the modified theme(.xpi) file to firefox, it shows an notification that the addon is corrupt .
    How do I install this theme?

    Firefox Aurora 33.0a2
    Windows 7 64 bit
    Thanks in advance.

  • VG

    ^^ It'll not work because it was designed for a very old version of Firefox. The file structure in Firefox has changed a lot since that time.

  • Hi,

    I've just found your page and it is exactly what i need. 3 possibilities, great.
    It's about GreasseMonkey. Instalation is refused on Firefox Android 39.0, as well as 2 first solutions.
    So, i used thr 'manual' one. The 3 booleans are add.
    After i reeboot, instal stil refused :(

    Do you have anouth to solve that ?
    Thanks for this page and your support.

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