Why do I receive an error message while trying to access some of my GNOME shell extension settings?
Solution 1:
I found a solution to this issue on this GitHub page. Basically, the problem is that some of the dependencies of the Clutter library are missing on Ubuntu (mine is 18.04 and the guy on GitHub is using 16.10). Just installing the following packages solves the problem:
sudo apt-get install gir1.2-clutter-1.0 gir1.2-clutter-gst-3.0 gir1.2-gtkclutter-1.0