DIY: Upgrade Incompatible Firefox Extensions

Mozilla Firefox 1.0 (Final version, not Preview) is released on 9 November 2004. I am sure many Firefox users already upgrade to the latest version because I can’t access Mozilla.org at the day!

Upgrade Firefox is as easy as 1-2-3, download and install in the current Firefox installation folder, done. However, if you are like me, use many extensions to add power to Firefox, some of the extensions will be founded incompatible with the version 1.o (even they previously work for 1.0PR).

Frankly, I do NOT use Firefox without extensions. After upgraded, Firefox will check for updates at its first launch. It is good but normally it failed to find extensions upgrade (extension author does not add update support, maybe?). Incompatible extensions will be disabled to ensure stability of Firefox.

Make Incompatible Extensions Work Again!

First of all, visit extention homepage for latest update(if any). The extention homepage is available in: Tools -> Extensions, right click on the incompatible extention(greyed out) and click “Visit Home Page”. Normally, extension authors will update their extensions to compatible with latest Firefox version.

In case you can’t find compatible upgrade from the author website, you can upgrade it by yourselves! Yes, you do it! No worry, it does not required any programming knowledge. :)

DIY: Upgrade Firefox Extension

1. DOWNLOAD(not install) the latest possible version of the Firefox extension. Example: an extension that support 1.0PR(version signature: 0.10) but failed to install on 1.0 (version signature: 1.0).
2. The downloaded extension is filename with .xpi, e.g: extension.xpi. Rename it to be zip file, e.g: extension.zip, then open the “zip file”(the extension file) with your zip tool(WinZip?).

   Tip: If you can’t see the file extension… Goto: Start -> Settings -> Control Panel ->Folder Options -> View tab -> Uncheck “Hide extension for known file types”, click OK button. (The instruction path is for WindowsXP, other Windows should have similar path)

3. There is a “install.rdf” file inside. Open the file for edit (I am editing in the zip tool, you may want to unzip the zip file before editing).
4. In the “install.rdf”, look for:
   <em :maxVersion>0.10</em>

   Change it to:
   <em :maxVersion>1.0</em>

5. Save the change and update to the zip file(or, zip it back if you have unzip the zip file).
6. In the Step 2, you have renamed the file to become a zip file. Now, rename the zip file back to extension file, example: extension.xpi
7. You have “upgraded” the extension, now install it by dragging the .XPI file into Firefox. It will install without error message of incompatible version!

Caution: Although this will install the extension, but you will get unexpected error if you try to install a incompatible(old version) extension. Use only self extension upgrade IF there is No update from the author AND the latest extension version is compatible with latest Firefox version. Example: Extensions that work on Firefox 1.0PR SHOULD also work in Firefox 1.0.

Thought:
Actually the Firefox extension .xpi file is a zip file. Therefore you can rename the extension and open with your zip tool to modify the file inside. The <em :maxVersion> in “install.rdf” is used to check for the largest version of Firefox that supported by the extension.

Since the changes from version 1.0PR to 1.0 Final is minor, the extensions that work on 1.0PR SHOULD also work for 1.0 Final. So, modify the “maxVersion” value will make the extension install in the Firefox without incompatible version error message.

I have made all my incompatible extensions(1.0PR) to works for 1.0! Hope this trick helps Firefox users to get their extensions working before original authors release upgrade version. :)

Remember: Get the official upgrade whenever possible to have additional feature/bug fix.