This is a fix for the ‘Padlock’ add-on for Firefox.  It applies to version 0.5.0 and should not be applied to anything else.

Padlock does not work when used with version 14 of Firefox and up.  Mozilla appeared to have removed the ‘identity-box-inner’ from the browser’s chrome (which was the highlighted button showing the name of the secure site you were using).  The result of removing that object causes a function to crash in Padlock when the security status of a site changes.  As a result, it appears as though the extension ‘simply doesn’t work’ when it is running, but the solution is actually quite simple when it’s tracked down.

If you want to fix the problem yourself (since it is an add-on to assist with security):

1. Open your profile folder.  If you don’t know how to do it, click Firefox’s Menu > Help > Troubleshooting Information > Show Folder (next to ‘Profile Folder’).
2. Close Firefox.
3. Find the file called {d09e32df-8610-4b33-b929-1e631b764130}.xpi in the profile folder.  This is the Padlock extension.
4. Back up (copy) the extension to another folder unrelated to Firefox or its profiles.
5. Open the extension’s files using a zip program (rename the extension to .zip if necessary).
6. Open folder ‘content’ and extract ‘padlock.xul’ only.
7. Open the file in Wordpad (or Notepad with Word Wrap turned off if you have to — I don’t really recommend either due to their formatting issues, but they do work in this instance).
8. Alter ‘identity-box-inner’ to ‘identity-box’.  It should only appear once, and be careful not to alter the content or formatting in the rest of the file.
9. Resave the file.
10. Replace the file back within the .zip file, which should overwrite the original.
11. Rename the file back to .xpi if necessary.
12. Restart Firefox and verify the extension now works (don’t forget to set the options)!

If Padlock ever gets updated, you should still pick up the new version as normal using the updater.