Refresh Firefox and re-install the add-on again. Instructions for refreshing Firefox are listed below.

The Refresh feature (called "Reset" in older Firefox versions) can fix many issues by restoring Firefox to its factory default state while saving your bookmarks, history, passwords, cookies, and other essential information.

Note: When you use this feature, you will lose any extensions, toolbar customizations, and some preferences. See the Refresh Firefox - reset add-ons and settings article for more information.

To Refresh Firefox:

1. Open the Troubleshooting Information page using one of these methods:
   • Click the menu button , click help and select Troubleshooting Information. A new tab containing your troubleshooting information should open.
   • If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.
2. At the top right corner of the page, you should see a button that says "Refresh Firefox" ("Reset Firefox" in older Firefox versions). Click on it.
3. Firefox will close. After the refresh process is completed, Firefox will show a window with the information that is imported.
4. Click Finish and Firefox will reopen.

Did this fix the problem? Please report back to us!

Thank you.

Tried it - unsuccessful - same error message. LastPass support team also unable to help (so far). I already knew I have one or more corrupted file paths (and maybe one mostly-harmless-but-annoying virus). I've been running XP too long, and running on the old computer too long - I think it's time to move all my documents to an external hard drive, completely wipe my internal drive, and download Xbuntu.

You may want to move to a more updated OS. I can personally hack an XP machine within two seconds and anyway it doesn't support all current browser versions.

I warmly recommend Xubuntu, I have it on a 2003 laptop and works decently.

Exactly what I had in mind.

Glad I could be of any help.

Good luck with your Linux installation.

if you need help with that, feel free to ask.

It is possible there is a problem with files in the profile folder that store the extensions registry.

Delete the extensions.* files (e.g. extensions.json, extensions.ini, extensions.sqlite) and compatibility.ini in the Firefox profile folder to reset the extensions registry.

• https://support.mozilla.org/en-US/kb/Profiles

New files will be created when required.

See "Corrupt extension files":

• https://support.mozilla.org/en-US/kb/unable-install-add-ons-extensions-or-themes
• http://kb.mozillazine.org/Unable_to_install_themes_or_extensions

If you see disabled or not compatible extensions in ""3-bar" menu button or Tools -> Add-ons -> Extensions" then check if there is a compatibility update available.

• click the cogwheel button (left of the Search bar) on the about:addons page to "Check for Updates"

If this didn't help then delete add-ons.json and possibly prefs.js in case there is a problem with preferences.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

nope - still won't install. I think the problem is corrupted file path(s) on my computer. Planning on moving on from XP to Linux Xbuntu.

OK, mattcamp. What I have in mind is to move my files to an external drive, download Xbuntu and save it on the external drive, completely wipe my internal drive, and then install Xbuntu. What's the best way - or a good way - to completely wipe my hard drive? When I do this, I imagine I'll lose the file paths to my external drive. How do I access what's there? Does Xbuntu come with a firewall, or will I have to find that separately? Any good free firewalls available out there? Anything else you think I'll need to know?

Copying your files to an external hard drive preserves your data and you can copy them back after you install Linux.

However, consider you might not be able to natively open files created for Windows applications, such as .exe files, unless using Wine.

If you install a new operating system by using the whole hard drive, that'll wipe your previous partition, overwriting your XP.

Each Linux system comes with a firewall, called iptables, which works from command line.

I don't understand what you mean by lose the file paths to my external drive honestly, so I'd like for you to clarify that.

Have you ever used Linux before? Keep in mind it's very different from Windows and there' s a certain learning curve to go through.

I have had several issues with this old computer. I don't know what problems, maybe some viruses, may be lurking in the background. (I have at least one apparent virus that Avast doesn't see or recognize.) I want to do more than just overwrite XP, I want to overwrite EVERYTHING and start over with an essentially blank disc before installing Linux. This is why I think a blank disc may not see or recognize my external hard drive or know how to find the data stored there.

I'd like to know the most effective way to do this.

No, I've not used Linux before, and yes I know it's very different and I'll have to unlearn and relearn how to use it and find my way around. I'm prepared for that (I think).

And yes, I'll probably have to download Wine to open some files (hopefully just initially before saving them in a new format).