If you go here:
Download the latest sources for Pango, GLib, and GTK.
First install Pango and GLib by opening a terminal and going into their respective folders, typing "./configure", "make", then "sudo make install".
Then install GTK the same way.
It also depends on the "Accessibility Toolkit" (ATK) but that was already installed on my system (and probably on yours too) and the link on their website to the latest ATK source was dead.
This fixed my problems
These are the source files I used: