Hi ur_avg.user, Firefox only shows Remove for extensions that were installed directly into your active profile folder. If the extension was installed into a shared location on the system, usually it would be managed through the software that installed it. If it doesn't provide a feature to remove the extension or hide it from Firefox, then you may need to go on a voyage of exploration to track it down and delete it yourself.

Ready?

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

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

In the first table on the page, on the Profile Folder row, click the "Show in Finder" button. If Finder highlights an icon with a semi-random name like a1b2c3d4.default, double-click it to display the contents of that profile folder.

Scroll down and find the extensions.json file. Resize the Finder window so you can see that Troubleshooting Information page, and drag and drop the extensions.json file onto it to replace the page.

At first, Firefox will show a jumble of text, but then it should display a structured viewer with various technical details on your extensions. If the data is "expanded" you can use the Find feature (Command+f) to skip to avira and then look for the path, which should be the precise place it is lurking on disk.

If you delete the file, then the next time you Quit Firefox and restart it, Firefox should detect the change and stop showing it on the Add-ons page.

Success?

hey whats up first i want to thank you for answering my question. However i have tried a similar solution before (And now this) and both times avira cannot be found when i search for it the first time i did it i did a search directly into finder (without draging into firefox) and i found one match and deleted it this time the search you had me do showed no matches on either of the three filters available for search (including all three) i may have to run a cleaner on my system to make sure there isnt something still locally here. If there is a less time consuming or easier solution that you know of, i would welcome it! thanks!

Hi ur_avg.user, how many extensions showed up in extensions.json'? If the list was not expanded, try using the Filter JSON box on the upper right of the structured display tab to figure out what numeric index it is listed under. Then after you clear out the Filter JSON box and get the whole list back, you can drill down into that one.

Did you try to open the extensions.json file in a Firefox tab?

That should open the file with the builtin JSON viewer.

• https://developer.mozilla.org/en-US/Tools/JSON_viewer

Click the arrow next to the addons key to expand this section. If you type Avira in the filter bar (top left) then you should only see this extension. Expand this entry as well. The path key should have the path of this extension. If you do not see the path key then clear the filter bar and scroll down to this entry, so make sure to remember its number.

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