Fix Outdated Firefox Extensions
in New Versions of Firefox

Firefox will notify you when it disables one of your installed extensions. You can also determine if an extension is disabled by clicking Tools, Add ons, Extensions in the Firefox menu. Disabled extentions appear as faded in the list and when selected, have an Enable button. If the extension is outdated the Enable button will not work. Try clicking the Find Updates button at the bottom of the Extensions window. If it finds and installs an update for your extension, you're done. If not, read on.

Firefox (v. 10+) no longer disables old add-ons automatically, but some add-ons may still be marked as incompatible when you download a new version of Firefox (e.g. Google Toolbar). The best solution is to install the Disable Add-on Compatibility Checks and see if the add-on you desire to use will actually work with your new version of Firefox. If the desired add-on does not work or crashes Firefox, disable it until a new version is available. (The Add-on Compatibility Reporter will no longer enable incompatible extensions for the current version of Firefox. It is now only used to report which are working/not working correctly.)

As an alternative, you can try hacking this yourself. Warning: This fix (changing the maximum version of an extension) may make the extension behave unpredictably or even crash the new version of Firefox. Follow these instructions at your own risk.

To change the maximum compatible version for an extension:

1. Enable the Sandbox:
   
   
   • Register for the Mozilla Sanbox if you have not already done so
   • Check the Show Sandbox box on Edit user profile, logging in if necessary.
2. Login to the Sandbox and in the same window, search for the Firefox Extension using the search box near the top right and click the link for the desired extension. (To be able to see extensions that have not been approved for the current version of Firefox, you must be logged into the Sandbox and have previously indicated to show the sandbox (see #1).) You can switch between searching the Sandbox and the Public area with the links at the left of the search box in the upper right.
3. The Install Now button will be red for extensions in the Sandbox. Right click the Install Now button and save the .xpi file, which is actually a renamed zip file.
4. Extract install.rdf from the zip file, but do not close your zip file window
5. Edit install.rdf (with an editor that recognizes line feed - HtmlKit, WordPad, etc, not NotePad), changing em:maxVersion and saving it
6. Go back to the zip file window,
7. delete install.rdf from the zip file
8. add the changed install.rdf to the zip file contents
9. Compress the zip file, replacing the original .xpi file
10. Drag the .xpi file to a blank portion of a Firefox window and follow the instructions in the small window that appears.
11. Restart Firefox
12. Test the extension. If it doesn't work or using it crashes Firefox, uninstall the extension and wait for an updated version.

When a new version of Firefox is installed, you'll need to repeat the procedure if the extension has not been updated for the new version. If you save the updated .xpi file you can just drag it into a Firefox window to install it, restart Firefox and then test the extension.