Updating add-ons

Automatic updating of extensions

You can configure Firefox and Thunderbird to update your extensions and themes automatically. (This is part of the Software Update feature.)

Disable auto-update for individual extensions

It is possible to prevent individual extensions from updating automatically even when you have the Software Update feature enabled. Further details can be found here.

This section is a stub. You can help MozillaZine Knowledge Base by expanding it.

Re-enabling disabled extensions

If you update Firefox or Thunderbird and find that an extension which was already installed on your previous version is no longer enabled, it is sometimes possible to re-enable it by going to "Tools -> Extensions", right-clicking on the extension, selecting "Enable" and then restarting the application. Note, however, that this will not work if the Extension Manager declares the extension to be incompatible with the new version of Firefox or Thunderbird.

Updating incompatible extensions for a new application version

The Extension Manager will inform you if an existing extension is incompatible with your current version of Firefox or Thunderbird, and it will prevent you from enabling it. However, in some cases the extension really is compatible, but its author has not yet updated its compatibility information to allow for the current version. If you believe this to be the case, you can update the compatibility information yourself using one of the following methods. Note that you could break your application by enabling an extension which really is incompatible with the application; if the aplication will not start up properly after you have enabled an incompatible extension, you should start up in Safe Mode, go to "Tools -> Extensions", and uninstall the problematic extension.

Changing the compatibility information manually

1. Download to your computer a copy of the extension (the ".xpi" file).
2. Extract (unzip) the .xpi file. It is simply a zipped file with an .xpi extension, so you should be able to use something like unzip or Stuffit-expander (on Mac) to extract it.
3. Open the "install.rdf" file with a text editor such as Notepad. Find a tagline like this showing the "maxVersion" number (in this case 1.0, but it may differ depending on the extension): <em:maxVersion>1.0</em:maxVersion>
4. Change the "1.0" to "1.5" or whatever you need. That tells the installer that the version can be installed with the corresponding version number of Firefox or Thunderbird.
5. Optionally, to indicate that you modified the extension for your own private use, you can also edit the lines describing the author/contributor and version of the extension.
6. Save the changes you made to the install.rdf file.
7. Create a zip archive containing all the files that were in the original .xpi file, including your modified install.rdf file. Rename it to "myExt.xpi" or whatever you like. The crucial thing here is to use ".xpi" for the file extension.
8. Strongly recommended: before installing the extension, make a temporary backup of your profile folder or at least of the "extensions" folder inside your profile folder, which contains the installed extensions. That way, if something goes wrong, you can revert the changes easily.
9. Finally, install the extension: If it's a Firefox extension, open the .xpi file from Firefox and it should install. If it's a Thunderbird extension, install it via the "Tools -> Extension" menu.

Using the Nightly Tester Tools extension

The Nightly Tester Tools extension allows you to force compatibility in a similar manner to the manual method above. Note that this extension has other features, and it will add some new items for power users and developers to the Help menu, and it will make changes to the titlebar wording (which can be reverted using the exension's Options dialog).