Try to disable all other extensions.

It is possible that there is a problem with the file(s) that store the extensions registry.

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

• https://support.mozilla.org/kb/Profiles

New files will be created when required.

See "Corrupt extension files":

• http://kb.mozillazine.org/Unable_to_install_themes_or_extensions
• https://support.mozilla.org/kb/Unable+to+install+add-ons

If you see disabled or not compatible extensions in "Firefox/Tools > Add-ons > Extensions" then click the Tools button at the left end side of the Search Bar ("Find Updates" button in older Firefox versions) to check if there is a compatibility update available.

If this hasn't helped then also delete the addons.sqlite file.

You can also try to delete the localstore.rdf file and the sessionstore.js file in the Firefox profile folder

Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost and you will have to recreate them (make a note or bookmark them if possible).

• http://kb.mozillazine.org/Session_Restore
• https://support.mozilla.org/kb/restore-previous-session

I deleted all the mentioned files in the profile folder, closing FF after removing each batch but still no English dictionary working or available. Yet, the English- gb dictionary is showing and 'Enabled' in Add-ons > languages.

It would be far easier if I could revert to FF 19.0 where everything worked....and i could work using Firefox. Is it possible I can go back to FF 19.0 where adding dictionaries was never a problem?

The en-GB dictionary works for me on Linux and is available as a choice in the Languages sub menu in the right-click context menu of a text area.

You can try to do an update check in Firefox/Tools > Add-ons > Extensions for this extension.

You can try to set the spellchecker.dictionary pref to "en-GB" (without quotes) on the about:config page.

Note that dictionaries need to be unpacked to make them work, so you can check the extensions folder of this dictionary to see if the two dictionary files are in its dictionaries folder.

• extensions\en-GB@dictionaries.addons.mozilla.org

You can use this button to go to the Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

Why cannot i just go back to the previous version of firefox without all the hassle of having to change all settings? ...and it still does not work..plus I lost all my tabs and bookmarks!

When I installed the GB dictionary there I had to do no unpacking it was just there for me. Plus considering how many millions of people in the UK who want the gb dictionary, it should be an automatic option available in the FF browser. The technology has been around for years!

Firefox should have done this automatically when you install a dictionary.

I was just asking you to see if you have that folder with the unpacked dictionary files to check if something went wrong during the installation.

What did you do that you lost the bookmarks?
Did you reset Firefox?

You should be able to restore the bookmarks from a JSON backup in the bookmarkbackups folder if you lost them.

• http://kb.mozillazine.org/Lost_bookmarks

It is not safe to go back to a previous Firefox version that has security vulnerabilities that have been fixed in the current Firefox version.

• http://www.mozilla.org/security/known-vulnerabilities/firefox.html

I have given up. It is taking too much time and I am getting nowhere. I have asked several times if I can revert to a previous version of FF that did work fine, but apparently there is nobody who can understand my English.

I'm going to go with Chrome and I set up the English-gb dictionary in their browser in seconds.