Install libdbusmenu-gtk4 by entering the following commands in the terminal:
sudo apt update sudo apt install libdbusmenu-gtk4
Description:
library for passing menus over DBus - GTK+ version
libdbusmenu passes a menu structure across DBus so that a program can create a menu simply without worrying about how it is displayed on the other side of the bus. . This package contains shared libraries to be used by GTK+ applications.
Homepage: https://launchpad.net/dbusmenu
Version: 16.04.1+18.04.20171206-0ubuntu1
Section: libs