Install libgtksourceview2.0-common by entering the following commands in the terminal:
sudo apt update sudo apt install libgtksourceview2.0-common
Description:
common files for the GTK+ syntax highlighting widget
GtkSourceView is a text widget that extends the standard GTK+ 2.x text widget GtkTextView. It improves GtkTextView by implementing syntax highlighting and other features typical of a source editor. . This package contains the language specifications files for Ada, C, C++, C#, CSS, ".desktop", ".diff" (patch), Fortran 95, GtkRC, Haskell, HTML, IDL, ".ini", Java, JavaScript, LaTeX, Lua, MSIL, Nemerle, Pascal, Perl, PHP, ".po" (gettext), Python, R, Ruby, sh, SQL, Tcl, Texinfo, VB.NET, Verilog, VHDL and XML.
Homepage: http://projects.gnome.org/gtksourceview/
Version: 2.10.5-3
Section: universe/misc