Have you tried downloading InformEnter from here or from another page?

Maybe your error could be due to file corruption or to Windows being short of available disk space, so I'd suggest to check for these possible reasons first.

If you can't download and/or install InformEnter, you might try LastPass , which is a fully compatible add-on.

I often use it to fill in forms for me, especially when applying for jobs.

Side note: I'm a volunteer here and I'm not paid by LastPass or anyone else to promote that specific product. I only know it works fine because I've been using it for years and that's what support is about.

Helping people based on your professional experience.

I don't know if this extension will work on Firefox 52. It uses the newer WebExtensions interface for Firefox extensions that has been getting new features with each release. Anyway, you could take a look:

Simple Form Fill

My 3-minute review:

After installation:

• After you've typed text into a field, you can select it (e.g., Shift+home if your cursor is at the end, or double-click or triple-click), right-click, click Simple Form Fill, then you can Add the selected text to the add-on's list.

• To fill that text in another field, you can right-click in the field, click Simple Form Fill, then click the text you want to insert.

Unfortunately, the menu item appears near the bottom of a very long context menu so it's far from handy to access. It also does not appear to have categories of data like the extension you were using before, so over time the list likely will become cumbersome.

The extension has an Autocomplete feature to show a drop-down below a field as you type. You can enable this on the Add-ons page, click the "Options" button (on Mac: "Preferences" button) for the extension and scroll down to the little settings area. Here you can enable/disable Autocomplete, and there's also a plain text list of your saved text that you could edit or, I assume, paste a bunch of lines into if you have a list you want to add. (I didn't try that.)

Autocomplete should simplify filling the data since you do not need to use the menu, but I tested with the built-in Form & Search History feature disabled, so I don't know whether they play well together.

The extension is under active development, so the developer might be willing to add some features to it to address these issues.

Thanks to those who replied. I am coming to believe that the problem is I am running Vista and apparently Firefox can't be upgraded from version 52. Even though my InformEnter was working fine under those conditions, it seems that neither it or Simple Form Fill or LastPass can install. I keep getting the same error code "...could not be installed because Firefox cannot modify the needed file"

I guess I'll try again once I upgrade to Windows 10 and the newest Firefox. Thanks for your suggestions.

Joe Garbin

Hi Joe, if you can't install any extensions, it may be that Firefox either does not have full privileges to the files in your profile folder, or that the files have become locked, which could happen in a crash.

Three thoughts:

(1) If you haven't already shut down and restarted Windows Vista since this problem began, you may want to try that first.

(2) If your malware cleaning tools damaged your existing Firefox profile, you can create a new one with some of your data to get a fresh start. This would be through the "Refresh" feature. If you haven't customized Firefox too heavily, then it wouldn't be too drastic a change. This article describes what you keep and what you lose when using Refresh: Refresh Firefox - reset add-ons and settings.

(3) If you don't want to use Refresh just yet and don't mind a little digging and poking, try renaming a couple settings files and see whether that allows Firefox to use/install extensions normally. Here's how:

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" or "Open Folder" button. This should launch a new window listing various files and folders in Windows Explorer.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > "power" button
• (menu bar) File > Exit

Set Windows to show all file extensions (by default, some file extensions are hidden) to avoid any confusion among similarly named files. This article has the steps for that: https://www.bleepingcomputer.com/tutorials/how-to-show-file-extensions-in-windows/

Now you're ready to hide a few files from Firefox so Firefox is forced to regenerate them from scratch. These are the key ones:

• extensions.ini - right-click this file and choose Rename. Then put an X at the end of the file name before the dot, and click away. It should change to extensionsX.ini.

• extensions.json - right-click this file and choose Rename. Then put an X at the end of the file name before the dot, and click away. It should change to extensionsX.json.

• if you see a file named extensions.json.bak take the same tack aqnd rename it to extensionsX.json.bak.

Then start Firefox back up again. Time to check the results:

(A) Check the Add-ons page to see whether has Firefox rediscovered any installed extensions and, if so, whether it will allow you to enable them. Either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions. Then check the list on the right side. Any extensions that Firefox installs on its own should be hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Note that extensions which are currently disabled cluster at the bottom.

(B) Try installing InformEnter and see whether you can do it now.

Any luck?

could not be installed because Firefox cannot modify the needed file.

This error message means that the extension needs to be unpacked and not place as the XPI file in the profile folder. There is normally a special unpack directive in its install.rdf file.

cor-el said

could not be installed because Firefox cannot modify the needed file.
This error message means that the extension needs to be unpacked and not place as the XPI file in the profile folder. There is normally a special unpack directive in its install.rdf file.

If that isn't happening automatically with any extension, should the original poster do a clean reinstall?

I checked the install.rdf file of the extension and it contains <em:unpack>true</em:unpack>, so Firefox would normally unpack the extension. If Firefox did unpack then something else might prevent Firefox from accessing this directory.

Thanks to all who replied and a big THANK YOU to jscher2000. I refreshed the profile and was able to reinstall InformEnter. Than I simply copied all of the data files I had prepared over the years (and separately saved), and now everything is back to "normal."

Thanks again,

Joe Garbin