I used Ubuntu 20.04 for a few months. This is the third I'm using Ubuntu 21.10 and I cannot install this GNOME extension: Emoji Selector
How can I fix this?
You are facing the major drawback of using Gnome Shell extensions from the Gnome Website. Gnome Shell unfortunately breaks extensions frequently. The author then needs to adapt the extension to mach the newer Gnome Shell version. If that does not happen, the user has a problem. There is nothing you can do except signalling the issue, and hoping the author will pick up, apart from going into coding yourself.
metadata.json file of the extension with a text editor.
As a workaround for the issue of incompatible GNOME extensions, you can find other tools that perform the same function and that are independent of GNOME Shell.
For a specific example, there are alternatives to the Emoji Selector extension mentioned in the question post. If you open Ubuntu Software and search for
emoji picker you'll find one such tool which you may want to check out.
I had the same problem in Ubuntu 20.04. I tried to install a hibernation menu using the two extensions bellow:
In Firefox the slider of the button was set to the 'On' state and nothing was happening. After refreshing the page, the button was set again to the 'Off' the state.
After I updated Ubuntu using Software Updater and rebooted the system, I successfully enabled the needed extensions. The following things were required (I do not yet know the exact order and how many times some points should be repeated to take proper effect):
r and pressing Enter.
After that the extensions were added to UI.
For installing GNOME extensions support, I used the instructions from this article: https://www.omgubuntu.co.uk/install-gnome-extensions-on-ubuntu
Here are the relevant steps from it:
Add the "GNOME Shell integration" add-on to the browser (Firefox or Chrome).
chrome-gnome-shell (also suitable for Firefox):
sudo apt install chrome-gnome-shell
sudo apt install gnome-tweaks
Here is a similar question: Why does nothing happen when trying to install dash to dock extension?