Install gtk2-engines-pixbuf by entering the following commands in the terminal:
sudo apt update sudo apt install gtk2-engines-pixbuf
Description:
pixbuf-based theme for GTK+ 2.x
GTK+ is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK+ is suitable for projects ranging from small one-off tools to complete application suites. . This package contains the pixbuf theme engine.
Homepage: http://www.gtk.org/
Version: 2.24.32-1ubuntu1
Section: graphics