Expect to see this error in Firefox 52+

GNOME Extensions are one of the real selling points of the GNOME desktop environment.

With a quick click you can extend, change and add features to the desktop directly from the web through the Firefox browser.

But installing these nifty feature extenders is shortly to become a touch more difficult. You won’t be able to install GNOME Extensions from the GNOME Extensions website using Firefox 52 or later.

Why? Well, Mozilla is dropping NPAPI support from Firefox (a change we’ve known about for a long time). Firefox 52, due next month, will the first version of the browser ship without support for NPAPI plugins (excusing Flash, cos whatever).

Also Read: Your Top 5 GNOME Shell Extensions

This feature deprecation will affect many popular plugins, including Silverlight, Adobe Acrobat and Java. It also affects the GNOME integration plugin that currently lets you install and manage GNOME extensions in Firefox out-of-the-box.

We’re not talking “click to play” disabled here, but total “you can’t run this at all” disabled.

Visit the GNOME Extensions website in Firefox 52 or later and you’ll see an error that reads “we cannot detect a running copy of gnome on this system”.

The good news is that if you want to fix this you can — and here’s how.

Enable GNOME Integration with Firefox

Install Gnome Shell Extensions With Firefox Chrome 24877
Install Gnome Shell Extensions With Firefox Chrome

You can continue to install, update, remove and manage GNOME Shell extensions using Firefox — but you will need to first install a  replacement add-on called GNOME Shell integration for Chrome, and install a desktop host connector.

Despite the name it’s not a Chrome-specific web extension. The add-on works all major browsers, as well as any minor ones, so long as they support the ‘Chrome Extensions API‘ (or the Firefox implementation known as ‘WebExtensions‘).

Part 1: The Extension

Screen Shot 2017-01-22 at 19.54.15

The GNOME Shell integration Firefox add-on is free, open-source software. For convenience you can install it from the Mozilla Add-Ons repo, but you will need to visit the page directly as it’s not (yet) considered stable:

GNOME Shell Integration Firefox Add-on

If you also want to add the same functionality to Google Chrome or Chromium, you can install the GNOME Shell Integration for Chrome Extension from the Chrome Web Store:

GNOME Shell Integration Chrome/ium Extension

Part 2: The Host Connector

adding the neosight ppa

The add-on above only does part of the job. You also need to install the native host connector. Without this you will see an error in Firefox that reads something like: ‘native host connector is not detected’.

You can install the host connector directly from the Ubuntu archives (no PPA) if you’re running Ubuntu 17.04 (Zesty Zapus).

Install the chrome-gnome-shell connector from Ubuntu Software

If you’re running an earlier version of Ubuntu — anything between 14.04 LTS (Trusty Tahr) and 16.10 (Yakkety Yak)— you need to add the following PPA to your software sources, update, and then install the ‘chrome-gnome-shell‘ package.

Open a new Terminal window and run the following commands:

sudo add-apt-repository ppa:ne0sight/chrome-gnome-shell
sudo apt-get update && sudo apt-get install chrome-gnome-shell

Once the host connector is installed locally you’re all set!

Open Firefox (or Chrome, if you installed the Chrome extension) and head to the GNOME Shell Extensions webpage. You should, after a few seconds, see everything working as intended.

gnome shell extensions webpage